Batteries including a flat plate design

• US 20040127952A1
• Filed: 02/07/2003
• Published: 07/01/2004
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Haasl, Benjamin J., Swanson, Lawrence D., Dillon, Reilly M., Victor, Tom G., Barr, A. Gordon, Kavanagh, Richard J., OʼPhelan, Michael J.
• Granted Patent: US 7,479,349 B2
• Time in Patent Office: Days
• US Class Current: 607/36
• CPC Class Codes: H01M 10/0404 Machines for assembling batteries
• CPC Class Codes: H01M 2220/00 Batteries for particular applications
• CPC Class Codes: H01M 50/107 having curved cross-section, e.g. round or elliptic H01M50/103, H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 6/005 Devices for making primary cells
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A battery having flat, stacked, anode and cathode layers. The battery can be adapted to fit within an implantable medical device.

Claims

1. A battery stack comprising:

a plurality of alternating anode and cathode layers, each of the cathode layers having a base layer and a cathode material layer attached to the base layer, the base layer including a cathode tab extending from a first position, each cathode tab having a thickness greater than a thickness of the cathode base layer; and

wherein each anode layer includes an anode tab extending from a second position.

2. The battery stack of claim 1, wherein each anode layer includes a base material layer and wherein each anode tab has a thickness greater than a thickness of the anode base material layer.

3. The battery stack of claim 1, wherein each of the anode and cathode layers includes a substantially non-rectangular shape.

4. The battery stack of claim 1, wherein the cathode material layer includes MnO₂.

5. A battery stack comprising:

a plurality of alternating anode and cathode layers, each of the anode layers having a base layer, the anode layer including an anode tab extending from a first position, the anode tab having a thickness greater than a thickness of the anode base layer; and

wherein each cathode layer includes a cathode tab extending from a second position.

6. The battery stack of claim 5, wherein each of the anode and cathode layers includes a substantially non-rectangular shape.

7. The battery stack of claim 5, wherein the cathode material layer includes MnO₂.

8. A battery stack comprising:

a first electrode layer including a first tab extending from a first position and a second tab extending from a second position; and

a second electrode layer including a tab, wherein the second electrode layer tab overlays the first tab when the second electrode layer is positioned over the first electrode layer.

9. The battery stack of claim 8, further comprising a third electrode layer having a tab, wherein the third electrode layer tab overlays the second tab when the third electrode layer is positioned over the first base electrode layer.

10. The battery stack of claim 8, wherein the first electrode layer includes a third tab extending from a third position, wherein the first tab, the second tab, and the third tab are electrically connected.

11. The battery stack of claim 10, further comprising a fourth electrode layer including a tab, wherein the fourth electrode layer tab overlays the third tab when the fourth electrode layer is positioned over the first base electrode layer.

12. The battery stack of claim 8, wherein the first electrode layer and the second electrode layers are cathode electrode layers.

13. The battery stack of claim 8, wherein the first electrode layer and the second electrode layers are anode electrode layers.

14. The battery stack of claim 8, further comprising a third electrode layer including a tab, wherein the third electrode layer tab overlays the second tab when the third electrode layer is positioned over the first base electrode layer, and wherein at least one of the second electrode layer or the third electrode layer has fewer tabs than the first base electrode layer.

15. The battery stack of claim 8, further comprising a third electrode layer including a tab, wherein the third electrode layer tab overlays the second tab when the third electrode layer is positioned over the first base electrode layer, wherein the second electrode layer tab and the first tab are connected together to form a first tab group and the third electrode layer tab and the second tab are connected together to form a second tab group, wherein each of the first tab group and the second tab group has a thickness less than the thickness of the sum of the first tab group and the second tab group.

16. A battery comprising:

a base cathode electrode layer having two or more tabs;

a base anode electrode layer having two or more tabs;

a secondary cathode electrode layer having fewer tabs than the base cathode electrode layer; and

a secondary anode electrode layer having fewer tabs than the base anode electrode layer;

wherein, the secondary cathode electrode layer has at least one tab overlaying and coupled to one of the two or more tabs of the base cathode electrode layer and the secondary anode electrode layer has at least one tab overlaying and coupled to one of the two or more tabs of the base anode electrode layer.

17. The battery of claim 16, wherein the base cathode electrode layer includes a tab for connecting to a battery terminal.

18. The battery of claim 16, wherein the base cathode electrode layer includes a metal sheet having a manganese dioxide (MnO₂) layer attached to a surface of the metal sheet.

19. The battery of claim 18, wherein the MnO₂ layer does not cover the two or more tabs of the base cathode electrode layer.

20. The battery of claim 16, wherein the base anode electrode layer includes a metal sheet including a lithium layer.

21. The battery of claim 20, wherein the lithium layer does not cover the two or more tabs of the base anode electrode layer.

22. A method of forming a battery stack having a plurality of electrode layers, the method comprising:

attaching a separator layer to each electrode layer of a battery stack; and

placing each electrode layer into a stacking fixture such that an edge of the separator layer of each electrode layer abuts a physical alignment element of the stacking fixture such that each electrode layer is aligned relative to the physical alignment element.

23. The method of claim 22, wherein the edge of each separator layer contacts two or more physical alignment elements.

24. The method of claim 22, wherein abutting a physical alignment element includes abutting two or more vertically oriented posts.

25. The method of claim 22, wherein abutting a physical alignment element of a stacking fixture includes abutting an inner surface of a battery case.

26. The method of claim 22, wherein placing includes using a controlled robotic arm to place each layer.

27. The method of claim 22, wherein placing includes manually placing each of the plurality of layers.

28. A method of maintaining alignment of a battery stack which includes a plurality of layers, the method comprising:

aligning each of the plurality of layers as each layer is being placed on top of a preceding layer of the battery stack; and

continually applying a compression force on the battery stack to hold each of the layers in that layer'"'"'s aligned position.

29. The method of claim 28, wherein continually applying a compression force includes continually applying a compression force to a top and a bottom surface of the battery stack.

30. The method of claim 28, wherein aligning includes using a vision alignment system.

31. A method of forming a battery stack, the method comprising:

placing a first battery layer onto a base pad which has a continually applied upward force applied to it such that the base pad forces the first battery layer upward while a pair of upper members apply a downward force on one or more top edge surfaces of the first battery layer;

aligning and placing a second battery layer on top of the first battery layer by using a placement member to press a central portion of the second battery layer into a central portion of the first battery layer while one or more top edge surfaces of the second battery layer remain above the pair of upper members;

moving the pair of upper members so that the one or more top edge surfaces of the second battery layer fall against a top surface of the first battery layer;

moving the pair of upper members back so that the pair of upper members are on top of the one or more top edge surfaces of the second battery layer;

removing the placement member; and

repeatedly aligning and placing a plurality of battery layers onto previously placed battery layers until a battery stack is formed.

32. The method of claim 31, wherein using a placement member includes using a controlled robotic arm to place each battery layer.

33. The method of claim 31, wherein using a placement member includes using a manually controlled tool.

34. A method of forming a battery stack for a flat battery, the method comprising:

sequentially placing a plurality of battery layers on top of each other such that each one of the plurality of battery layers is, in turn, a top layer of a battery stack; and

continually applying a compression force between a bottom layer of the battery stack and the top layer of the battery stack until each of the plurality of battery layers is placed.

35. The method of claim 34, wherein sequentially placing includes using a controlled robotic arm to place each battery layer.

36. The method of claim 34, wherein sequentially placing includes manually placing each of the plurality of battery layers.

37. The method of claim 34, wherein continually applying a compression force includes alternately employing a placement member and an upper holding member to apply a force on the top layer of the battery stack.

38. The method of claim 34, further including aligning each of the plurality of layers while placing the layer on the battery stack.

39. An apparatus for forming a battery stack, the apparatus comprising:

a base pad for holding a stack of individual battery layers; and

an upper member movable over the stack to hold down each of the individual layer as the layers are placed onto the stack by a placement member;

wherein, the upper member is adapted to move while the placement member holds down each battery layer as each battery layer is placed onto the stack such that the stack is continually held down by either the placement member or the upper member.

40. The apparatus of claim 39, wherein the placement member includes a controlled robotic placement arm.

41. The apparatus of claim 39, wherein the placement member includes a manually manipulated tool.

42. The apparatus of claim 39, wherein the upper member includes a plastic film supported at each end of the film.

43. The apparatus of claim 42, wherein the plastic film includes a roll of plastic film which is configured to be indexed to provide a fresh section of plastic film.

44. The apparatus of claim 42, wherein the plastic film has a thickness of approximately 0.005 inches or less.

45. The apparatus of claim 42, wherein the plastic film has a thickness of approximately 0.001 or less.

46. A battery comprising:

a case having a curved interior surface; and

a battery stack including;

a first battery stack portion having an anode layer and a cathode layer and having a first edge surface that confronts the curved interior surface of the case; and

a second battery stack portion having an anode layer and a cathode layer and having a second edge surface that confronts the curved interior surface of the case;

wherein the first edge surface is set back from the second edge surface to define a profile generally congruent to a profile of the curved interior surface.

47. The battery of claim 46, wherein the battery includes a third battery stack portion having an anode layer and a cathode layer and having a third edge surface that confronts the curved interior surface of the case, wherein the third edge surface is set back from the second edge surface.

48. The battery of claim 46, wherein the first and second battery stacks have respective third and fourth edges, wherein the third edge surface is set back from the fourth edge surface.

49. An implantable medical device comprising the battery of claim 46.

50. A battery comprising:

a plurality of anode layers;

a plurality of separators; and

a plurality of cathode layers;

wherein the battery includes a layered stack structure having alternating anode layers and cathode layers with one or more separators interposed between each adjacent anode layer and cathode layer, and further wherein an outer perimeter edge surface of at least one of the cathode layers is offset from an outer perimeter edge surface of at least one of the anode layers that is adjacent to the cathode layer.

51. The battery of claim 50, wherein the battery includes a flat, stacked battery structure such that the anode layer, the separator, and the cathode layer are in a layered, stacked configuration.

52. The battery of claim 50, wherein the cathode layer includes a MnO₂ material.

53. A battery comprising:

an anode layer comprising a flat sheet having a first outer perimeter;

a separator layer; and

a cathode layer comprising a flat sheet having a second outer perimeter;

wherein the battery is constructed as a stacked, layered structure with the separator interposed between the cathode layer and the anode, and further wherein the second outer perimeter of the cathode layer is completely offset from the first outer perimeter of the anode layer.

54. The battery of claim 53, wherein the cathode layer includes a MnO₂ material.

55. A battery comprising:

a housing having a wall which includes an integrally formed annular structure defining a feedthrough hole, the integrally formed annular structure including an inward facing cylindrical surface;

an electrode assembly located within the housing and including an anode and a cathode;

a feedthrough post extending through the feedthrough hole; and

an electrically insulating member having an outer surface abutting the inward facing cylindrical surface and an inner hole, wherein the feedthrough post extends through the inner hole and has one end connected to a portion of the electrode assembly and a second end exposed externally to the housing.

56. The battery of claim 55, wherein the housing includes a base portion and a lid portion and the feedthrough hole is within the lid portion.

57. The battery of claim 55, wherein the electrode assembly includes a plurality of anode sub-assemblies and cathode sub-assemblies arranged in a layered stack.

58. The battery of claim 55, wherein the electrically insulating member includes a glass member.

59. A battery comprising:

a housing including a wall having an integrally formed cylindrical surface extending from the wall and defining a feedthrough hole in the wall;

an electrode assembly located within the housing and including an anode and a cathode;

a cylindrical insulating member located within the feedthrough hole and abutting the inner surface of the integrally formed cylindrical surface, the cylindrical insulating member having a hole; and

a feedthrough post having a first end connected to the electrode assembly, the feedthrough post extending through the hole of the cylindrical member.

60. The battery of claim 59, wherein the electrode assembly includes a plurality of anode sub-assemblies and cathode sub-assemblies arranged in a layered stack.

61. The battery of claim 59, wherein the cylindrical insulating member includes a glass member.

62. An implantable medical device comprising:

an outer housing;

a battery within the housing;

the battery comprising;

a housing defining a chamber; and

a plurality of electrode layers within the chamber;

wherein, the plurality of electrode layers includes a base electrode layer having a plurality of base tabs and a plurality of secondary electrode layers, each of the plurality of secondary electrode layers having a tab, wherein at least one of the plurality of secondary electrode layers has fewer tabs than the base electrode layer;

wherein, each of the plurality of secondary electrode layers has at least one tab overlaying and coupled to one of the plurality of base tabs.

63. The medical device of claim 62, wherein

the plurality of secondary electrode layers are arranged in a first layer group, a second layer group, a third layer group, and a fourth layer group;

the plurality of base tabs comprise a first base tab, a second base tab, a third base tab, and a fourth base tab;

the first layer group overlays the first base tab forming a first tab group, the second layer group overlays the second base tab forming a second tab group, the third layer group overlays the third base tab forming a third tab group, and the fourth layer group overlays the fourth base tab forming a fourth tab group;

each tab group having a thickness less than the thickness of the sum of the first tab group, the second tab group, the third tab group, and the fourth tab group.

64. A method of forming a battery, the method comprising:

providing a plurality of non-rectangularly shaped cathodes, each non-rectangularly shaped cathode having the same approximate shape as the other non-rectangularly shaped cathodes, each cathode having a tab extending from the cathode;

providing a plurality of non-rectangularly shaped anodes, each non-rectangularly shaped anode having the same approximate shape as the other non-rectangularly shaped anodes and cathodes, each anode having a tab extending from the anode, each anode tab in a different position from each cathode tab;

stacking the plurality of anodes and cathodes into a battery stack with a separator between each anode and each cathode;

connecting the cathode tabs to each other;

connecting the anode tabs to each other;

placing the battery stack into an non-rectangularly shaped battery case having approximately the same shape as the anodes and the cathodes; and

connecting the anode tabs and cathode tabs to respective anode and cathode terminals.

65. The method of claim 64, wherein preparing the cathodes includes pressing an MnO₂ powder material into a cathode base layer.

66. The method of claim 64, wherein preparing the cathodes includes attaching an MnO₂ paste onto a cathode base layer.

67. The method of claim 64, wherein preparing the cathodes includes heat sealing each cathode in a separator.

68. A battery stack comprising:

a first cathode layer including a first tab extending from a first position;

a first anode layer including a second tab extending from a second position;

a second cathode layer having a tab, wherein the second cathode layer tab overlays the first tab; and

a second anode layer including a tab, wherein the second anode layer tab overlays the second tab;

wherein the first and second cathode layers include a metal sheet having a manganese dioxide (MnO₂) layer attached to a surface of the metal sheet.

69. The battery of claim 68, wherein the MnO₂ layer does not cover the tab of the cathode electrode layers.

70. The battery of claim 68, wherein the first and second anode layers include a metal sheet including a lithium layer.

71. The battery of claim 70, wherein the lithium layer does not cover the tabs of the anode electrode layers.

72. A method of sealing a backfill port of a battery, the method comprising:

fitting a backfill port plug into a hole in a battery case; and

welding the port plug to the battery case as the port plug is being fitted into the hole.

73. The method of claim 72, wherein the port plug has a larger diameter than a diameter of the hole in the battery case such that there is an interference fit between the port plug and the hole.

74. The method of claim 72, wherein the port plug includes a spherical ball-shape.

75. The method of claim 72, wherein the port plug includes a cap shape.

76. The method of claim 72, further comprising providing a second, laser weld between the plug and the case.

77. A method of sealing a backfill port of a battery, the method comprising:

using a first welding electrode to push a backfill port plug into a hole in a battery case;

placing a second electrode against the battery case; and

delivering a welding energy from the first electrode to the second electrode to weld the port plug to the battery case.

78. The method of claim 77, wherein the welding energy is delivered while the first electrode is pushing the backfill port plug into the hole.

79. The method of claim 77, wherein the welding energy is delivered after the first electrode has pushed the backfill port plug into the hole.

80. The method of claim 77, wherein the backfill port plug is dimensioned to provide an interference fit between the plug and the battery case.

81. The method of claim 77, further comprising providing a second weld around a head of the plug after the first weld, wherein the second weld is a laser weld.

82. A battery stack comprising:

an alternating sequence of anodes and cathodes having a separator between each anode and each cathode, wherein each separator is connected to an adjacent separator to form a substantially sealed pocket around each cathode.

83. The battery stack of claim 82, wherein a tab of each cathode is exposed beyond the substantially sealed pocket.

84. The battery stack of claim 82, wherein each cathode includes MnO₂.

85. A battery stack comprising an alternating sequence of anodes and cathodes, wherein each cathode has a first separator on one side and a second separator on a second side, wherein the first separator and the second separator are connected to each other around at least a portion of their edges.

86. The battery stack of claim 85, wherein the first separator and the second separator define a flange at the connection of the first separator and the second separator, wherein the flange extends beyond an edge of the cathode and encloses the edge of the cathode.

87. The battery stack of claim 85, wherein the connection between the first separator and the second separator includes a heat seal.

88. A battery stack comprising an alternating sequence of anodes and cathodes, wherein each anode has a first separator on one side and a second separator on a second side, wherein the first separator and the second separator are connected to each other around at least a portion of their edges.

89. The battery stack of claim 88, wherein the first separator and the second separator define a flange at the connection of the first separator and the second separator, wherein the flange extends beyond an edge of the anode and encloses the edge of the anode.

90. The battery stack of claim 88, wherein the connection between the first separator and the second separator includes a heat seal.

91. A method comprising:

placing an electrode between first and second separator sheets; and

attaching the first separator sheet to the second separator sheet along a periphery of the electrode to substantially enclose the electrode between the first and second separators.

92. The method of claim 91, wherein attaching the first separator sheet to the second separator sheet includes heat sealing the separator sheets together.

93. The method of claim 91, wherein attaching the first separator sheet to the second separator sheet includes ultrasonic welding the separator sheets together.

94. The method of claim 91, wherein attaching the first separator sheet to the second separator sheet includes hot die sealing the separator sheets together.

95. The method of claim 91, wherein attaching the first separator sheet to the second separator sheet includes inductive heat sealing the separator sheets together.

96. The method of claim 91, wherein the electrode includes a cathode.

97. The method of claim 91, wherein the electrode includes an anode.

98. A method of forming a cathode for a battery, the method comprising:

mounting a cathode carrier strip into a fixture having a cavity such that at least a portion of the cathode carrier strip is located within the cavity;

depositing a cathode powder into the cavity;

vibrating the fixture; and

pressing the cathode powder onto the carrier strip.

99. The method of claim 98, wherein the cathode carrier strip is mounted substantially vertically within the cavity.

100. The method of claim 98, further including sieving the cathode powder before the cathode powder is deposited into the cavity.

101. The method of claim 98, wherein pressing the powder onto the carrier strip includes pressing at approximately 16-21 tons per square inch.

102. The method of claim 98, wherein a precise, pre-determined amount of cathode powder is deposited into the cavity.

103. A method of forming a cathode for a battery, the method comprising:

mounting a cathode carrier strip within a fixture such that the carrier strip is oriented substantially vertical within a cavity of the fixture;

depositing a cathode powder into the cavity; and

pressing the powder onto the carrier strip.

104. The method of claim 103, wherein the cathode powder includes MnO₂.

105. The method of claim 103, wherein pressing the powder onto the carrier strip includes driving a pair of opposing press head members towards each other on opposing sides of the carrier strip.

106. The method of claim 103, further comprising vibrating the fixture before pressing the powder onto the carrier strip.

107. A method of forming a cathode for a battery, the method comprising:

providing a clamp member having a cavity;

depositing a cathode powder into the cavity;

mounting a cathode carrier strip over the cavity;

placing a shim over the cathode carrier strip, the shim having a cavity;

depositing a cathode powder into the shim cavity; and

pressing the cathode powder onto the carrier strip.

108. The method of claim 107, wherein the cathode powder includes MnO₂.

109. The method of claim 107, wherein a precise, pre-determined amount of cathode powder is deposited into the clamp member cavity and a precise, pre-determined amount of cathode powder the shim cavity.

110. A method of forming interconnections of a battery stack, the method comprising:

connecting together one or more anode connection members of one or more anodes and one or more cathode connection members of one or more cathodes; and

electrically isolating the one or more anode foils from the one or more cathode foils.

111. The method of claim 110, wherein electrically isolating includes cutting a portion of the anode connection members and the cathode connection members.

112. The method of claim 110, wherein each of the cathode connection members has a thickness approximately the same as or greater than a thickness of a main body of each of the one or more cathodes.

113. The method of claim 110, wherein each of the anode connection members has a thickness approximately the same as or greater than a thickness of a main body of each of the one or more anodes.

114. A method comprising:

positioning an anode connection member having a distal section and a proximal section and a cathode connection member having a distal section and a proximal section so that the distal section of the anode connection member overlays the distal section of the cathode connection member;

connecting the anode connection member and the cathode connection member; and

forming a separation in the distal section of the anode connection member and the distal section of the cathode connection member, wherein the proximal section of the anode connection member is electrically isolated from the proximal section of the cathode connection member.

115. The method of claim 114, wherein connecting the anode connection member and the cathode connection member includes welding a portion of the anode connection member to a portion of the cathode connection member.

116. A battery having a battery stack constructed by the method of claim 114.

117. A method comprising:

providing a pair of anodes, each anode having an anode connection member having a distal section and a proximal section;

providing a cathode having a cathode connection member having a distal section and a proximal section;

sandwiching the cathode between the pair of anodes and positioning each anode connection member and the cathode connection member so that the distal section of each anode connection member overlays or underlays the distal section of the cathode connection member, wherein the cathode connection member has a thickness such that the cathode connection member substantially fills a gap between the anode connection members;

connecting the anode connection members and the cathode connection member; and

forming a separation in the distal section of the anode connection members and the distal section of the cathode connection member, wherein the proximal section of the anode connection members is electrically isolated from the proximal section of the cathode connection member.

118. The method of claim 117, wherein connecting the anode connection member and the cathode connection member includes welding a portion of the anode connection member to a portion of the cathode connection member.

119. A method comprising:

providing a pair of cathodes, each cathode having an cathode connection member having a distal section and a proximal section;

providing a anode having a anode connection member having a distal section and a proximal section;

sandwiching the anode between the pair of cathodes and positioning each cathode connection member and the anode connection member so that the distal section of each cathode connection member overlays or underlays the distal section of the anode connection member, wherein the anode connection member has a thickness such that the anode connection member substantially fills a gap between the cathode connection members;

connecting the cathode connection members and the anode connection member; and

forming a separation in the distal section of the cathode connection members and the distal section of the anode connection member, wherein the proximal section of the cathode connection members is electrically isolated from the proximal section of the anode connection member.

120. The method of claim 119, wherein connecting the cathode connection member and the anode connection member includes welding a portion of the cathode connection member to a portion of the anode connection member.

121. A method of connecting a terminal to a case, the method comprising:

providing a protrusion extending from a base surface of a metal terminal;

applying opposite charges between the case and the metal terminal; and

bringing the terminal towards the case such that the protrusion is facing the case until the protrusion melts or vaporizes and the terminal becomes attached to the case at the base surface of the terminal.

122. The method of claim 121, wherein the metal terminal and the metal case are formed of dissimilar metals.

123. The method of claim 121, wherein an electric field develops between the protrusion and the case when the terminal is brought towards the case.

124. A method comprising:

providing a terminal including a base having a terminal extension extending from a first surface of the base and a protrusion extending from an opposing, second surface of the base;

applying opposite electrical charges between the terminal and the case; and

bringing the terminal towards the case with the protrusion facing the case until an arc goes between the protrusion and the case, whereby the terminal is welded to the case.

125. The method of claim 124, wherein the terminal is positively charged and the case is negatively charged.

126. The method of claim 124, wherein the terminal is negatively charged and the case is positively charged.

127. A method comprising:

providing a terminal including a base having a terminal extension extending from a first surface of the base and a protrusion extending from an opposing, second surface of the base;

applying opposite electrical charges between the terminal and the case; and

bringing the terminal towards the case with the protrusion facing the case until the protrusion touches the case and melts, whereby the terminal is welded to the case.

128. The method of claim 127, wherein the terminal is positively charged and the case is negatively charged.

129. The method of claim 127, wherein the terminal is negatively charged and the case is positively charged.

130. A tape applicator for a battery stack, the tape applicator comprising:

a tape dispenser including a strip of tape; and

a battery stack holder located proximate the tape dispenser and adapted to rotate a battery stack around a first axis such that the strip of tape is applicable to a first surface of the stack as the stack rotates around the first axis, wherein the tape dispenser and the holder are movable relative to each other around a second axis such that the strip of tape can have two or more orientations relative to the battery stack.

131. The tape applicator of claim 130, wherein the second axis is perpendicular to the first axis.

132. The tape applicator of claim 130, wherein the second axis approximately intersects the first axis.

133. A method comprising:

applying a strip of tape from a tape dispenser upon a first surface of a battery stack while rotating the battery stack around a first axis;

rotating the tape dispenser around a second axis which is substantially perpendicular to the first axis when the strip of tape reaches an edge of the first surface of the battery stack; and

applying the strip of tape upon a second surface of the battery stack while rotating the battery stack around the first axis.

134. The method of claim 133, wherein the first axis is a longitudinal axis of the battery stack.

135. The method of claim 133, wherein the second axis approximately intersects the first axis.

136. The method of claim 133, wherein when the strip of tape reaches the edge of the first surface of the battery stack, the tape dispenser is rotated such that the angle of the strip of tape on the first surface and the angle of the strip of tape on the second surface are substantially equal relative to a tangent line of the edge of the stack.

137. A battery comprising:

a battery stack including a plurality of alternating anode and cathode layers; and

a one-piece insulating sheath dimensioned to substantially surround the battery stack, the insulating sheath including an opening for receiving the battery stack within the insulating sheath and an integral flap to at least partially cover the opening when the battery stack is within the insulating sheath.

138. The battery of claim 137, wherein the insulating sheath includes one or more spaces for extension tabs of the anode and cathode layers to extend through the insulating sheath.

139. The battery of claim 137, wherein the battery is mounted within the insulating sheath, there is a seam on only one side of the insulting sheath.

140. A method of insulating a battery stack from a battery case, the method comprising:

placing a battery stack through an opening in an insulating sheath to position the battery stack within the insulating sheath; and

folding a flap of the insulating sheath over the opening.

141. The method of claim 140, wherein the flap is integrally connected to the insulating sheath.

142. The method of claim 140, wherein an upper edge of the flap is attached to a surface of the insulating sheath proximate the opening.

143. A battery having a power of approximately 2 to 5 amps and a capacity of approximately 2.0 amp-hours or greater, the battery comprising:

an MnO₂ cathode;

an anode opposing the MnO₂ cathode; and

a battery case holding the MnO₂ cathode and the anode;

wherein the battery case has a volume of approximately 9.0 cm³ or less.

144. The battery of claim 143, wherein the battery case has a volume of approximately 8.64 cm³.

145. The battery of claim 143, wherein the battery case has a volume between approximately 8.0 cm³ and 9.0 cm³.

146. The battery of claim 143, wherein the battery case has a volume between approximately 8.5 cm³ and 9.0 cm³.

147. The battery of claim 143, wherein the anode includes lithium.

148. The battery of claim 147, wherein the ratio of lithium to MnO₂ is approximately 1.27.

149. A battery having a power of approximately 2 to 5 amps and a capacity of approximately 2.0 amp-hours or greater, the battery comprising:

a plurality of alternating discrete anode and cathode layers formed into a stacked structure, wherein each of the cathode layers includes MnO₂.

150. The battery of claim 149, wherein each of the anodes includes lithium.

151. A battery having a power of approximately 2 to 5 amps and a capacity of approximately 2.0 amp-hours or greater, the battery comprising:

an anode and a cathode having a chemical composition capable of providing a substantially constant charge time for the battery.

152. The battery of claim 151, wherein the substantially constant charge time is between approximately 5 to 10 seconds.

153. The battery of claim 151, wherein the substantially constant charge time is between approximately 6 to 7 seconds.

154. The battery of claim 151, wherein the anode and cathode are mounted within a case, the case having a volume of approximately 9.0 cm³ or less.

155. The battery of claim 151, wherein the anode and cathode include

a battery case holding the MnO₂ cathode and the anode;

wherein the battery case has a volume of approximately 9.0 cm³ or less.

156. The battery of claim 151, wherein the anode and cathode comprise a plurality of alternating discrete anode and cathode layers formed into a stacked structure.

157. A battery comprising:

a battery stack;

a battery case having a backfill hole, wherein the battery stack is located within the battery case; and

a terminal having a first end extending away from the case and a second end mounted within the backfill hole and coupled to the case.

158. The battery of claim 157, wherein the second end of the terminal has a spherical shape.

159. The battery of claim 157, wherein the second end of the terminal includes a cap-shaped plug.

160. The battery of claim 157, wherein the battery stack includes a plurality of alternating anode and cathode layers.

161. The battery of claim 157, wherein the second end of the terminal is welded to the battery case to seal the backfill hole.