Estimating the state of charge of MH-Ni batteries by measuring their stable internal pressure

JOURNAL OF POWER SOURCES

卷:343

Article

Zhang, Jian¹  Shao, Guangjie²  Guo, Weiwen^1,2  Lou, Yuwan¹  Xia, Baojia¹ 

[1] Chinese Acad Sci, Shanghai Inst Microsyst & Informat Technol, Shanghai 200050, Peoples R China

[2] Yanshan Univ, Coll Environm & Chem Engn, Qinhuangdao 066004, Hebei, Peoples R China

关键词: MH-Ni battery;    Hybrid electric vehicle;    Stable internal pressure;    State of charge;    Estimate;   

DOI  :  10.1016/j.jpowsour.2017.01.031

来源: Elsevier

【 摘 要 】

Nickel metal hydride (MH-Ni) batteries are widely used in hybrid electric vehicles (HEVs). Estimating a battery's state of charge (SOC) remains challenging in practical applications, and it is also the core technology. Because MH-Ni batteries exhibit high rates of self-discharge and have flat and broad charge discharge voltage plateaus, the estimation of their SOC through their voltage, current, internal resistance, and temperature is not accurate and has a large cumulative error. In this study, a new method for estimating SOC based on battery's stable internal pressure is proposed using the one-to-one correspondence between the hydrogen equilibrium pressure and the reversible hydrogen-storage capacity described by the pressure concentration isotherm (P-C-T)curves of hydrogen storage alloys. The actual SOC and the stable internal pressure of the battery have a one-to-one correspondence after the battery was stored at different temperatures and SOCs, and this relationship is maintained after different cycling number and after four years of storage.(C)2017 Elsevier B.V. All rights reserved.

【 授权许可】

Free