Method for predicting battery charge limit, and method and apparatus for rapidly charging battery using same

Patent metadata

Field	Value
Publication number	US-2018292461-A1
Application number	US-201615574356-A
Country	US
Kind code	A1
Filing date	Aug 4, 2016
Priority date	Aug 18, 2015
Publication date	Oct 11, 2018
Grant date	—

Abstract

Provided are a method of predicting a battery charge limit not to cause lithium (Li)-plating, and a battery charging method and apparatus capable of quickly charging a battery based on the battery charge limit. A battery charge limit prediction method according to the present disclosure includes (a) fabricating a three-electrode cell including a unit cell and a reference electrode, (b) measuring a negative electrode potential (CCV) based on a state of charge (SOC) while charging the three-electrode cell, and (c) determining a point at which the negative electrode potential is not dropped but starts to be constant, as a lithium (Li)-plating occurrence point, and setting the Li-plating occurrence point as a charge limit.

First claim

What is claimed is:

1 . A battery charge limit prediction method comprising:
(a) fabricating a three-electrode cell comprising a unit cell and a reference electrode; (b) measuring a negative electrode potential (CCV) based on a state of charge (SOC) while charging the three-electrode cell; and (c) determining a point at which the negative electrode potential is not dropped but starts to be constant, as a lithium (Li)-plating occurrence point, and setting the Li-plating occurrence point as a charge limit.

2 . The battery charge limit prediction method of claim 1 , wherein a point at which a negative electrode potential gradient is changed in a graph of the negative electrode potential based on the SOC is set as the charge limit.

3 . The battery charge limit prediction method of claim 1 , wherein charge limits at different charging rates are obtained by repeatedly performing the operations (b) and (c) at the charging rates and a charging protocol is obtained by combining the charge limits.

4 . A battery charging method for charging a battery by setting a point at which a negative electrode potential of a battery is not dropped but starts to be constant at an initial charging rate higher than 1C, as a lithium (Li)-plating occurrence point, setting the Li-plating occurrence point as a charge limit, and reducing the charging rate in a stepwise manner when the charge limit is reached.

5 . The battery charging method of claim 4 , wherein a point at which the negative electrode potential is not dropped but starts to be constant and at which a negative electrode potential gradient is changed is set as the charge limit.

6 . The battery charging method of claim 4 , wherein the initial charging rate is 1.5C to 5C.

7 . The battery charging method of claim 4 , wherein the charging rate is reduced to a subsequent charging rate when the charge limit is reached during charging, and charging is performed until a state of charge (SOC) of the battery is 80%.

8 . A battery charging method comprising:
acquiring data by measuring a negative electrode potential based on a state of charge (SOC) at different charging rates in a test of a three-electrode cell comprising a unit cell and a reference electrode; obtaining a protocol for changing a charging rate in a stepwise manner by determining a point at which the negative electrode potential is not dropped but starts to be constant, as a lithium (Li)-plating occurrence point, and setting the Li-plating occurrence point as a charge limit; and charging a battery based on the protocol.

9 . The battery charging method of claim 8 , wherein a point at which the negative electrode potential is not dropped but starts to be constant and at which a negative electrode potential gradient is changed is set as the charge limit.

10 . The battery charging method of claim 8 , wherein the charging rates used to acquire the data range from 0.25C to 5C.

11 . The battery charging method of claim 8 , wherein the protocol comprises an initial charging rate higher than 1C.

12 . The battery charging method of claim 8 , wherein the protocol comprises an initial charging rate of 1.5C to 5C.

13 . The battery charging method of claim 8 , wherein the protocol comprises charging rates reduced in a stepwise manner, and charging voltage information after charging at each charging rate.

14 . A battery charging apparatus comprising:
a power supply unit configured to output a charging voltage input from a commercial power source; and a battery charging unit configured to charge a battery by outputting the charging voltage input from the power supply unit, as a charging current to the battery, and to control the charging current output to the battery, to be changed in a stepwise manner by changing the charging current when a charging voltage of the battery reaches a preset level, wherein the battery charging unit charges the battery by adjusting the charging current in a stepwise manner based on a protocol for changing a charging rate in a stepwise manner by determining a point at which a negative electrode potential of the battery is not dropped but starts to be constant, as a lithium (Li)-plating occurrence point, and setting the Li-plating occurrence point as a charge limit.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Hyo-Mi
• Lee Hyeok-Moo
• Oh Song-Taek
• Lee Sol-Nip

Classifications

• G01R31/36

  Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] · CPC title

• H02J7/00 Primary

  Circuit arrangements for charging or discharging batteries or for supplying loads from batteries · CPC title

• H02J7/94

  in response to battery current · CPC title

• H01M10/44

  Methods for charging or discharging (circuits for charging H02J7/00) · CPC title

• H01M10/425

  Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00) · CPC title