| 摘要 |
A secondary battery is implemented as an assembly of a plurality of battery modules. An ECU calculates a deterioration indicator quantitatively indicating a degree of deterioration of a battery module for each of the plurality of battery modules, and detects as a module to be replaced, a battery module of which deterioration indicator has reached a prescribed replacement level. The ECU further extracts a module to additionally be replaced, which should be replaced simultaneously with the module to be replaced above, from battery modules of which deterioration indicator has not reached the replacement level, among the plurality of battery modules. |
| 主权项 |
1. A device for determining deterioration of a battery implemented as an assembly of a plurality of battery modules, comprising:
a deterioration diagnosis unit configured to calculate on-board a deterioration indicator quantitatively indicating a degree of deterioration for each battery module in the plurality of battery modules; a detection unit configured to detect on-board a deteriorated battery module to be replaced, from among said plurality of battery modules, based on a comparison between the calculated deterioration indicator of the deteriorated battery and a prescribed replacement level; an extraction unit configured to extract on-board, when said detection unit detects said deteriorated battery module, a nearly-deteriorated battery module to be replaced simultaneously with said deteriorated battery module, from non-deteriorated battery modules of which the deterioration indicator has not yet reached said replacement level, among said plurality of battery modules; and a guidance information generation unit configured to evaluate which of replacement of entire said assembly and partial replacement of only said deteriorated and nearly-deteriorated battery modules is more advantageous in terms of cost, in accordance with a total number of detected said deteriorated battery modules and extracted said nearly-deteriorated battery modules; wherein: the on-board calculation of the deterioration diagnosis unit, the on-board detection of the detection unit, and the on-board extraction of the extraction unit are executed by at least one electronic control unit mounted in the device, said battery is a lithium ion battery, said deterioration diagnosis unit includes:
a deterioration parameter obtaining unit configured to obtain a positive electrode capacity retention ratio, a negative electrode capacity retention ratio, and a battery capacity fluctuation amount of said lithium ion battery through deterioration diagnosis based on open-circuit voltage characteristics indicating change in open-circuit voltage with change in capacity of said lithium ion battery,a lithium deposition amount estimation unit configured to separate the obtained battery capacity fluctuation amount into: (i) a first fluctuation amount corresponding to age-related deterioration, and (ii) a second fluctuation amount corresponding to deterioration due to deposition of lithium based on the obtained positive electrode capacity retention ratio and said negative electrode capacity retention ratio, in accordance with correspondence found in advance between said positive electrode capacity retention ratio, said negative electrode capacity retention ratio and the first fluctuation amount in said battery capacity fluctuation amount,said lithium deposition amount estimation unit is configured to obtain the first fluctuation amount based on the obtained positive electrode capacity retention ratio, the obtained negative electrode capacity retention ratio, and correspondence found in advance between the positive electrode capacity retention ratio, the negative electrode capacity retention ratio and the first fluctuation amount, andsaid lithium deposition amount estimation unit is configured to obtain said second fluctuation amount by subtracting the obtained first fluctuation amount from the obtained battery capacity fluctuation amount, and said deterioration indicator includes said second fluctuation amount of each said battery module. |
