HEV NiMH Battery Storage And Performance Degradation Study

Due to the increasingly energy crisis, environment pollution and greenhouse effect, car industry has more roughly restrictions on energy saving and emission reduction。Hybrid vehicles attract the attention of the whole world as its high efficiency and low emission. Power battery is one of the key components in hybrid vehicle and electric vehicle, and long-term storage andmaintainance to power battery is a very important process during the usage of new energy car, however, domestic and abroad correlative research is lack.At present, bad charge-discharge performance and high self-discharge rate are the main disadvantages of Ni-MH battery, which hinder the popularization and scale application of Ni-MH battery. Charged Ni-MH batteries are in a state of higher Gibbs energy( G) compared to that of their discharged states. This is a kind of phenomenon that electrode voltage decrease as time goes on, we call this phenomenon as “self-discharge”.Capacity loss after charge has great relationship with self-discharge action. Self-discharge action will make battery change from high-energy state after charging to low-energy state, and whether capacity that loss can restore will depends on self-discharge principle and discharge condition. Therefore, research on self-discharge action of Ni-MH battery is very significant to usage of battery and battery performance forecast.So an experiment is designed in this paper to research how different maintainance methods influencing onthe performance decreasing of Ni-MH battery, and belowis the main research content:① Ni-MH battery self-discharge principle wasanalyzed, and an experiment which research Ni-MH battery maintain method is designed;② Research on how charge-discharge conditions influence on power battery performance;③ Research on how maintenance period influence on power battery performance;④ Research on how standing time influence onpower battery performance;⑤ Research on how charging rate influence on power battery performance;⑥ Research on how storage SOC influence power battery performance。...