Method and apparatus for quantitative analysis of battery performance, and electronic device therewith

1 . A method for quantitative analysis of battery performance, comprising:

performing a full charging process or a full discharging process on a battery cluster, and determining differential capacities versus voltage of a plurality of cells in the battery cluster at different times, wherein a constant current exists in at least part of a time period of the full charging process or the full discharging process;

determining first times and first states of charge (SOC) when the differential capacities versus voltage of the cells reach a first peak and second times and second SOCs when the differential capacities versus voltage of the cells reach a second peak, and determining capacity parameters of the cells according to the first times, the first SOCs, the second times, and the second SOCs, wherein the second SOCs are greater than the first SOCs; and

performing quantitative analysis on the battery cluster according to the capacity parameters of the plurality of cells,

wherein when the full charging/discharging process comprises a full charging process, in the full charging process the constant current exists in at least a time period from a charging beginning time to a largest one of the second times of the plurality of cells, and the full charging process begins when the battery cluster reaches a discharging ending voltage and ends when the battery cluster reaches a charging ending voltage;

wherein when the full charging/discharging process comprises a full discharging process, in the full discharging process the constant current exists in at least a time period from a smallest one of the second times of the plurality of cells to a discharging ending time, and the full discharging process begins when the battery cluster reaches the charging ending voltage and ends when the battery cluster reaches the discharging ending voltage; and

wherein the determining the capacity parameters of the cells according to the first times, the first SOCs, the second times, and the second SOCs comprises:

determining, according to a first SOC k,I peak and a second SOC k,II peak of the cell k in the battery cluster, a difference ΔSOC k between the SOCs of the cell k when reaching the first peak and the second peak, wherein ΔSOC k =SOC k,II peak −SOC k,I peak ; and

determining a difference ΔQ k between capacities of the cell k when reaching the first peak and the second peak, and determining a maximum capacity Q kmax of the cell k, wherein Q kmax =100%×ΔQ k /ΔSOC k .

2 . The method according to claim 1 , wherein the capacity parameter of a cell k in the battery cluster comprises a capacity C k,chrend by which the cell k is to be further charged when a charging ending moment of the battery cluster is reached and a capacity C k,disend by which the cell k is to be further discharged when a discharging ending moment of the battery cluster is reached.

3 . The method according to claim 2 , wherein the performing quantitative analysis on the battery cluster according to the capacity parameters of the plurality of cells comprises:

determining, according to a capacity by which each of the cells is to be further charged at a charging ending moment of the each cell, the earliest fully charged cell j in the battery cluster and the earliest fully charged cell j′ other than the cell j, wherein

if the cell j is replaced, an effective charge capacity of the battery cluster is increased by C j′,chrend ; and

if the cell j is discharged alone to an ending voltage after discharging of the battery cluster ends, the effective charge capacity of the battery cluster is increased by min [C j′,chrend , C j,disend ].

4 . The method according to claim 2 , wherein the performing quantitative analysis on the battery cluster according to the capacity parameters of the plurality of cells comprises:

determining, according to a capacity by which each of the cells is to be further discharged at a discharging ending moment of the each cell, the earliest fully discharged cell i in the battery cluster and the earliest fully discharged cell i′ other than the cell i, wherein

if the cell i is replaced, an effective discharge capacity of the battery cluster is increased by C i′,disend ; and

if the cell j is charged alone to an ending voltage after charging of the battery cluster ends, the effective discharge capacity of the battery cluster is increased by min [C i′,disend , C i,chrend ].

5 . The method according to claim 1 , wherein the determining capacity parameters of the cells according to the first times, the first SOCs, the second times, and the second SOCs further comprises:

determining a charging ending SOC k,end of the cell k at the charging ending moment of the battery cluster according to a target time and a target SOC when the cell k reaches a target peak and the maximum capacity Q kmax of the cell k, wherein the target peak is the first peak or the second peak, and the target time is the corresponding first time or second time; and

determining, based on the charging ending SOC k,end of the cell k, the capacity C k,chrend by which the cell k is to be further charged when the charging ending moment of the battery cluster is reached and the capacity C k,disend by which the cell k is to be further discharged when the discharging ending moment of the battery cluster is reached, wherein the capacity C k,chrend by which the cell is to be further charged at the charging ending moment and the capacity C k,disend by which the cell is to be further discharged at the discharging ending moment satisfy:

C k,chrend =(1− SOC k,end )× Q kmax ;

C k,disend =SOC k,end ×Q kmax −∫ t k,begin t k,end Idt,

wherein t k,begin represents a beginning time of the full charging/discharging process of the cell k, t k,end represents an ending time of the full charging/discharging process of the cell k, and I represents a current value in the full charging/discharging process.

6 . The method according to claim 5 , wherein the determining capacity parameters of the cells according to the first times, the first SOCs, the second times, and the second SOCs further comprises:

determining a charge capacity C k,charge of the cell k and a discharge capacity C k,discharge of the cell k, wherein the charge capacity C k,charge and the discharge capacity C k,discharge satisfy:

C k,charge =∫ t k,begin t k,end Idt +(1− SOC k,end )× Q kmax ;

C k,discharge =SOC k,end ×Q kmax .

7 . The method according to claim 5 , wherein in a case that the full charging/discharging process comprises the full charging process, the charging ending SOC k,end of the cell k satisfies:

SOC k,end =SOC k,T peak +∫ t k,T peak t k,chrend Idt/Q kmax ; and

in a case that the full charging/discharging process comprises the full discharging process, the charging ending SOC k,end of the cell k satisfies:

SOC k,end =SOC k,T peak +∫ t k,disbegin t k,T peak Idt/Q kmax ,

wherein SOC k,T peak represents an SOC of the target peak, t k,T peak represents the target time of the target peak, t k,chrend represents a charging ending time of the cell k, and t k,disbegin represents a discharging beginning time of the cell k.

8 . An apparatus for quantitative analysis of battery performance, comprising:

a charging/discharging module, configured to perform a full charging process or a full discharging process on a battery cluster, and determine differential capacities versus voltage of a plurality of cells in the battery cluster at different times, wherein a constant current exists in at least part of a time period of the full charging process or the full discharging process;

a processing module, configured to determine first times and first states of charge (SOC) when the differential capacities versus voltage of the cells reach a first peak and second times and second SOCs when the differential capacities versus voltage of the cells reach a second peak, and determine capacity parameters of the cells according to the first times, the first SOCs, the second times, and the second SOCs, wherein the second SOCs are greater than the first SOCs; and

an analysis module, configured to perform quantitative analysis on the battery cluster according to the capacity parameters of the plurality of cells,

wherein when the full charging/discharging process comprises a full charging process, in the full charging process the constant current exists in at least a time period from a charging beginning time to a largest one of the second times of the plurality of cells, and the full charging process begins when the battery cluster reaches a discharging ending voltage and ends when the battery cluster reaches a charging ending voltage;

wherein when the full charging/discharging process comprises a full discharging process, in the full discharging process the constant current exists in at least a time period from a smallest one of the second times of the plurality of cells to a discharging ending time, and the full discharging process begins when the battery cluster reaches the charging ending voltage and ends when the battery cluster reaches the discharging ending voltage; and

wherein the determining capacity parameters of the cells according to the first times, the first SOCs, the second times, and the second SOCs comprises:

determining, according to a first SOC k,I peak and a second SOC k,II peak of the cell k in the battery cluster, a difference ΔSOC k between the SOCs of the cell k when reaching the first peak and the second peak, wherein ΔSOC k =SOC k,II peak −SOC k,I peak ; and

determining a difference ΔQ k between capacities of the cell k when reaching the first peak and the second peak, and determining a maximum capacity Q kmax of the cell k, wherein Q kmax =100%×ΔQ k /ΔSOC k .

9 . An electronic device, comprising a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and runnable on the processor, wherein the transceiver, the memory, and the processor are connected through the bus, and when the computer program is executed by the processor, the steps in the method for quantitative analysis of battery performance according to claim 1 are implemented.

10 . A non-transitory tangible computer-readable storage medium, storing a computer program therein, wherein when the computer program is executed by a processor, the steps in the method for quantitative analysis of battery performance according to claim 1 are implemented.