Rapid evaluation method for state of health of ex-service battery module of electric vehicle

Abstract

The invention relates to a rapid evaluation method for a state of health of an ex-service battery module of an electric vehicle. According the rapid evaluation method, the state of health (SOH) of thebattery is compared with voltage Lorenz dispersion sigma<-> in a discharging process, the correlation between the SOH and a sigma<-> value during the discharging process are analyzed, and the workload is not increased since an operating voltage during the charging and discharging processes of the battery can be acquired in real time by means of a battery management system without additional acquisition; the acquired operating voltage is not limited to a certain state of charge (SOC) value as long as it is in a corresponding SOC interval, and the method is more convenient; and the calculationof the voltage Lorenz dispersion sigma<-> is based on a result of voltage equalization in the SOC interval, and the calculation result is more precise. The rapid evaluation method can realize rapid evaluation of the SOH of an ex-service battery of the electric vehicle by just calculating the voltage Lorenz dispersion sigma<-> during the discharging process of the ex-service battery module to be detected, so as to carry out consistent rapid sorting, thereby achieving the purposes of simple, convenient and low-cost recycling of the ex-service battery.

Description

technical field [0001] The invention relates to an energy recycling technology, in particular to a rapid assessment method for the health state of a retired battery module of an electric vehicle. Background technique [0002] In 2017, the sales of electric vehicles in my country exceeded 770,000. With the rapid development of the electric vehicle industry, the research on the cascade utilization of retired power batteries is becoming a new research hotspot. It is generally believed that when the capacity of the power battery drops to about 80% of the nominal capacity, these power batteries need to be retired from the electric vehicle due to frequent charging and mileage anxiety, but the retired battery still has a certain remaining capacity. It can still be reused in some energy storage applications, such as portable backup power supplies, electric forklift power supplies, and renewable energy storage. [0003] Since the power battery has been used in electric vehicles for...

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Problems solved by technology

[0004] Aiming at the time-consuming, labor-intensive and high-cost problems of residual energy detection in the process of reusing decommissioned batteries, the present invention proposes a rapid evaluation method for the health status of decommissioned battery modules of electric vehicles, which compares the health status SOH of the battery with the voltage during the discharge process Lorenz dispersion To compare and analyze the SOH and discharge process The correlation between values, in order to achieve the purpose of consistent and rapid sorting of decommissioned batteries, and truly realize the low-cost goal of reusing decommissioned batteries

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