CHARGING METHOD AND CHARGER FOR NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY

• US 20110267001A1
• Filed: 06/15/2010
• Published: 11/03/2011
• Est. Priority Date: 09/18/2009
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kashiwagi, Katsumi, Ugaji, Masaya, Hiraoka, Tatsuki, Yamamoto, Taisuke
• Granted Patent: US 8,541,986 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• 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 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

In a charging method for a non-aqueous electrolyte secondary battery which includes a positive electrode including a lithium-containing composite oxide as an active material, a negative electrode including an alloy-formable negative electrode active material, and a non-aqueous electrolyte, a voltage of the secondary battery is detected. When the detected value is smaller than a predetermined voltage x, charging is performed at a comparatively small current value B. When the detected value is equal to or greater than the predetermined voltage x and smaller than a predetermined voltage z, charging is performed at a comparatively great current value A. When the detected value is equal to or greater than the predetermined voltage z and smaller than a predetermined voltage y, charging is performed at a comparatively small current value C. When the detected value is greater than the predetermined voltage y, constant-voltage charging is performed or charging is terminated. Here, x<z<y.

Claims

1. A charging method for a non-aqueous electrolyte secondary battery which comprises a positive electrode including a lithium-containing composite oxide as an active material, a negative electrode including an alloy-formable negative electrode active material, and a non-aqueous electrolyte, the charging method comprising the steps of:

(a) detecting a state of charge of the secondary battery;

(b) comparing the detected state of charge with a predetermined value X and a predetermined value Y satisfying Y>

X; and

(c) on the basis of the comparison result,

(i) when the detected state of charge is equal to or higher than the predetermined value Y, performing constant-voltage charging or terminating charging,

(ii) when the detected state of charge is equal to or higher than the predetermined value X and lower than the predetermined value Y, performing constant-current charging at a current value A until the detected state of charge reaches a predetermined state of charge, or

(iii) when the detected state of charge is lower than the predetermined value X, performing constant-current charging at a current value B satisfying B<

A.

2. The charging method for a non-aqueous electrolyte secondary battery in accordance with claim 1, further comprising the steps of

(d) comparing the detected state of charge with a predetermined value Z satisfying Y>

Z>

X, and

when the detected state of charge is equal to or higher than the predetermined value Z and lower than the predetermined value Y, performing constant-current charging at a current value C satisfying C<

A.

3. The charging method for a non-aqueous electrolyte secondary battery in accordance with claim 1, wherein the step of detecting a state of charge includes a step of detecting an open circuit voltage or a closed circuit voltage of the secondary battery.

4. The charging method for a non-aqueous electrolyte secondary battery in accordance with claim 1, wherein the predetermined value X is a state of charge of 5 to 30%.

5. The charging method for a non-aqueous electrolyte secondary battery in accordance with claim 2, wherein the predetermined value Z is a state of charge of 65 to 90%.

6. The charging method for a non-aqueous electrolyte secondary battery in accordance with claim 1, wherein the current value B is 10 to 60% of the current value A.

7. The charging method for a non-aqueous electrolyte secondary battery in accordance with claim 2, wherein the current value C is 10 to 75% of the current value A.

8. The charging method for a non-aqueous electrolyte secondary battery in accordance with claim 2, wherein the current value C is greater that the current value B.

9. A charger for a non-aqueous electrolyte secondary battery which comprises a positive electrode including a lithium-containing composite oxide as an active material, a negative electrode including an alloy-formable negative electrode active material, and a non-aqueous electrolyte, the charger comprising:

a voltage detection unit for detecting a voltage of the secondary battery;

a state-of-charge detection unit for detecting a state of charge of the secondary battery on the basis of the detected voltage;

a current supply circuit for supplying a current from an external or internal DC power supply to the secondary battery with changing a value of the current stepwise;

a switch for switching an electrically connected state between the secondary battery and the current supply circuit;

a judgment unit for comparing the detected state of charge with a predetermined value X and a predetermined value Y satisfying Y>

X, to make judgment on the detected state of charge; and

a control unit for controlling the switch and the current supply circuit on the basis of the judgment of the judgment unit, in such a manner that

(i) when the detected state of charge is equal to or higher than the predetermined value Y, performing constant-voltage charging or terminating charging,

(ii) when the detected state of charge is equal to or higher than the predetermined value X and lower than the predetermined value Y, performing constant-current charging at a current value A until the detected state of charge reaches a predetermined state of charge, or

(iii) when the detected state of charge is lower than the predetermined value X, performing constant-current charging at a current value B satisfying B<

A.