SILICON NANOCOMPOSITE NANOFIBERS

• US 20150099186A1
• Filed: 02/28/2013
• Published: 04/09/2015
• Est. Priority Date: 03/02/2012
• Status: Abandoned Application

• Current Assignee: Cornell University
• Original Assignee: Cornell University
• Inventors: Joo, Yong Lak, Hansen, Nathaniel S., Cho, Daehwan, Kim, Kyoung Woo, Kim, Yong Seok
• Application Number:
  US14/382,423
• Publication Number:
  US 20150099186A1
• Time in Patent Office: Days
• US Class Current: 429/231.8
• CPC Class Codes: D01D 5/003 the material being a polymer solution or dispersion D01D5/0053 takes precedence
• CPC Class Codes: D01D 5/0069 characterised by the spinning section, e.g. capillary tube, protrusion or pin
• CPC Class Codes: D01D 5/14 with flowing liquid or gaseous stretching media , e.g. solution-blowing
• CPC Class Codes: D01F 1/09 for making electroconductive or anti-static filaments
• CPC Class Codes: D01F 1/10 Other agents for modifying properties
• CPC Class Codes: D01F 9/20 from polyaddition, polycondensation or polymerisation products D01F9/145, D01F9/16, D01F9/18 take precedence
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 4/0469 Electroforming a self-supporting electrode; Electroforming of powdered electrode material
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/1393 of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/1395 of electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/446 Composite material consisting of a mixture of organic and inorganic materials
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries

Abstract

Provided herein are silicon nanocomposite nanofibers and processes for preparing the same. In specific examples, provided herein are nanocomposite nanofibers comprising continuous silicon matrices and nanocomposite nanofibers comprising non-aggregated silicon domains.

Claims

1-57. -57. (canceled)

58. A composition comprising a plurality of nanocomposite nanofibers comprising a carbon backbone, the carbon backbone comprising nanoparticles embedded therein, the nanoparticles comprising silicon, and the composition comprising on average at least 50 elemental wt % silicon.

59. The composition of claim 58, wherein the composition comprises on average less than 30 wt % carbon.

60. The composition of claim 58, wherein the nanoparticles further comprise silicon dioxide.

61. The composition of claim 58, wherein the silicon comprises crystalline silicon.

62. The composition of claim 58, wherein the nanoparticles have an average diameter of less than 100 nm and an aspect ratio of at least 100.

63. The composition of claim 58, wherein the nanofibers comprise on average at least 75 elemental wt. % of silicon.

64. The composition of claim 58, wherein the nanoparticles are non-aggregated.

65. The composition of claim 58, comprising XRD two theta peaks at three or more of the following:

28.37°

±

0.03, 47.20°

±

0.03, 56.09°

±

0.03, 69.02°

±

0.03, and 76.37°

±

0.03.

66. A lithium ion battery comprising an anode, a cathode, and a separator, the anode comprising a composition of claim 58.

67. The lithium ion battery of claim 66, wherein the anode has a specific energy capacity of at least 1500 mAh/g on a first cycle at 0.1 C.

68. The lithium ion battery of claim 66, wherein the anode has a specific energy capacity of at least 400 mAh/g on a 98^th cycle at 0.1 C.

69. A process of producing a nanocomposite nanofiber, the process comprising gas-assisted electrospinning a fluid stock, the fluid stock comprising a combination of silicon nanoparticles, an organic polymer, and a fluid.

70. The process of claim 69, wherein the fluid is aqueous.

71. The process of claim 69, wherein the organic polymer is polyvinylalcohol (PVA), polyacrylonitrile (PAN), or polyvinylpyrrolidone (PVP).

72. The process of claim 69, wherein the weight-to-weight ratio of the silicon nanoparticles to organic polymer is at least 1:

4.

73. The process of claim 72, wherein the weight-to-weight ratio of the silicon nanoparticles to organic polymer is at least 1:

2.

74. The process of claim 69, further comprising thermally carbonizing the nanofiber.

75. The process of claim 73, wherein the nanofiber is thermally carbonized at a temperature of about 500 C to about 2000 C.

76. The process of claim 73, wherein the nanofiber is thermally carbonized under inert conditions.

77. The process of claim 69, wherein the nanofiber comprises at least 50 elemental wt % silicon.

78. The process of claim 69, wherein the nanofiber comprises at least 50 elemental wt % silicon and less than 30 wt % carbon.