Methods for fast-charging and detecting lithium plating in lithium ion batteries

Patent metadata

Field	Value
Publication number	US-2019031035-A1
Application number	US-201715664704-A
Country	US
Kind code	A1
Filing date	Jul 31, 2017
Priority date	Jul 31, 2017
Publication date	Jan 31, 2019
Grant date	—

Abstract

Methods for fast-charging batteries while minimizing lithium plating (LP) comprise charging the battery in a first phase at a near-maximum charging current, subsequently charging the battery in a second phase by decreasing the charging current while charging in order to maintain the anode potential equal to or above an anode potential threshold, and subsequently charging the battery in a third phase at constant cell potential such that the cathode potential remains below a cathode potential threshold. LP can be detected by determining the derivative of the charging current and examining the derivative for smooth curves or local discontinuities, wherein a smooth curve indicates the absence of LP and a curve with a local discontinuity indicates the presence of LP. A fast-charging profile can be defined by plotting the cell potential vs. the charging current from the first phase, the second phase, and the third phase to define a fast-charging profile.

First claim

1 . Method for fast-charging a lithium battery, wherein the battery comprises an anode, a cathode electrically connected to the anode via a circuit, and a lithium ion-containing electrolyte in contact with the anode and the cathode, and wherein the battery is charged by directing current from a power supply to the circuit, the method comprising:
charging the battery in a first phase at a near-maximum charging current; subsequently charging the battery in a second phase by decreasing the charging current while charging in order to maintain the anode potential equal to or above an anode potential threshold; and subsequently charging the battery in a third phase such that the cathode potential remains below a cathode potential threshold.

2 . The method of claim 1 , wherein the near-maximum charging current is determined by the limitations of the battery hardware and/or the external charging hardware.

3 . The method of claim 1 , wherein during the second phase the anode potential remains substantially constant close to, but not below, the minimum anode potential threshold.

4 . The method of claim 1 , wherein the first phase ends when the anode potential reaches the anode potential threshold.

5 . The method of claim 1 , wherein the second phase ends when the cell potential reaches a maximum cell potential threshold.

6 . The method of claim 1 , wherein the cell potential remains substantially constant during the third phase.

7 . The method of claim 1 , wherein the charging current is decreased while charging during the third phase such that the cathode potential remains close to, but not above, the cathode potential threshold.

8 . The method of claim 1 , further comprising subsequently ending battery charging when the charging current reaches a minimum value and maintaining the battery in an open-circuit state in a fourth phase.

9 . The method of claim 1 , further comprising determining the minimum anode potential threshold by
first:
measuring the charging current during one or more of the second phase or the third phase;
determining the derivative of the measured charging current with respect to time; and
examining the derivative data over the second phase and/or the third phase to determine whether the derivative data presents a smooth curve or a curve with a local discontinuity, wherein a smooth curve indicates the absence of lithium plating and a curve with a local discontinuity indicates the presence of lithium plating; and
second:
iteratively implementing the battery charging method using a higher anode potential threshold than the previous iteration if lithium plating occurred during the previous iteration or using a lower anode potential threshold than the previous iteration if no lithium plating occurred during the previous iteration.

10 . The method of claim 9 , further comprising measuring the potential of a characteristic of the battery, determining the derivative of the measured potential with respect to time or charge, and examining the derivative data over the first phase, the third phase, and/or the fourth phase.

11 . The method of claim 10 , wherein the measured potential of a characteristic of the battery comprises one or more of the anode potential, the cathode potential, and/or the cell potential.

12 . A method for determining whether lithium plating occurs while charging a battery, wherein the battery comprises an anode, a cathode electrically connected to the anode via a circuit, and a lithium ion-containing electrolyte in contact with the anode and the cathode, and wherein the battery is charged by directing current from a power supply to the circuit, the method comprising:
charging the battery in a first phase at a near-maximum charging current; subsequently charging the battery in a second phase by decreasing the charging current while charging in order to maintain the anode potential equal to or above an anode potential threshold; subsequently charging the battery in a third phase such that the cathode potential remains below a cathode potential threshold; optionally subsequently ending battery charging when the charging current reaches a minimum value and maintaining the battery in an open-circuit state in a fourth phase; measuring the charging current during one or more of the second phase and the third phase; determining the derivative of the measured charging current with respect to time; and examining the derivative data over the second phase and/or the third phase to determine whether the derivative data presents a smooth curve or a curve with a local discontinuity, wherein a smooth curve indicates the absence of lithium plating and a curve with a local discontinuity indicates the presence of lithium plating.

13 . The method of claim 12 , further comprising measuring the potential of a characteristic of the battery, determining the derivative of the measured potential with respect to time or charge, and examining the derivative data over the first phase, the third phase, and/or the fourth phase.

14 . The method of claim 13 , wherein the measured potential of a characteristic of the battery can comprise the anode potential, the cathode potential, and/or the cell potential.

15 . The method of claim 13 , wherein the measured potential of the characteristic of the battery is IR compensated.

16 . A method for defining a fast-charging profile for a lithium battery wherein the battery comprises an anode, a cathode electrically connected to the anode via a circuit, and a lithium ion-containing electrolyte in contact with the anode and the cathode, and wherein the battery is charged by directing current from a power supply to the circuit, the method comprising:
during a three-phase, or optionally four-phase, calibration battery charging:
charging the battery in a first phase at a near-maximum current until the battery anode potential substantially reaches a minimum anode potential threshold;
subsequently in a second phase decreasing the charging current while charging the battery such that the anode potential remains substantially near, but not below, the minimum anode potential threshold;
subsequently in a third phase charging the battery at a substantially constant cell potential and continuously decreasing the charging current such that cathode potential does not exceed a cathode potential threshold;
measuring cell potential with respect to time during the first phase, the second phase, and the third phase; and
measuring charging current with respect to time during the first phase, the second phase, and the third phase; and

plotting the measured cell potential vs. the measured charging current to define a fast-charging profile.

17 . The method of claim 16 , further comprising determining the minimum anode potential threshold by
first:
measuring the charging current during one or more of the second phase or the third phase;
determining the derivative of the measured charging current with respect to time; and
examining the derivative data over the second phase and/or the third phase to determine whether the derivative data presents a smooth curve or a curve with a local discontinuity, wherein a smooth curve indicates the absence of lithium plating and a curve with a local discontinuity indicates the presence of lithium plating; and
second:
iteratively implementing the battery charging method using a higher anode potential threshold than the previous iteration if lithium plating occurred during the previous iteration or using a lower anode potential threshold than the previous iteration if no lithium pla

Assignees

• Gm Global Tech Operations Llc

Inventors

• Koch Brian J

Classifications

• H02J7/00

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

• H01M10/4257

  Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries · CPC title

• H01M10/052

  Li-accumulators · CPC title

• B60L2240/547

  Voltage · CPC title

• B60L58/10

  for monitoring or controlling batteries · CPC title