Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5149416 | Journal of Power Sources | 2017 | 5 Pages |
Abstract
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.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Jian Zhang, Guangjie Shao, Weiwen Guo, Yuwan Lou, Baojia Xia,