1. Improvement of the conductive network of positive electrodes and the performance of Ni-MH battery
- Author
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Hideshi Maki, Kousuke Nakayama, Minoru Mizuhata, Hiroshi Inoue, and Katsuya Morimoto
- Subjects
Valence (chemistry) ,Materials science ,Cell voltage ,Renewable Energy, Sustainability and the Environment ,Analytical chemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,chemistry ,Electrode ,Constant current ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Composite material ,Electronic conductivity ,0210 nano-technology ,Electrical conductor ,Cobalt - Abstract
The pretreatment to modify the valence of cobalt by discharging at 0.2 C rate for 7.5 h before the first initial activation charge process is effective in improving the surface electronic conductivity among fine particles of positive electrode active materials. The discharge curves indicate the same locus within 1800 cycles, and the capacity of the pretreated battery is stable for over 4000 cycles. However, in-situ cell pretreatment with constant current has negative influence on other components. During the constant current pretreatment, the cell voltage rapidly falls to −0.5 V in the first 10 s of in-situ pretreatment. Therefore, we investigate the pretreatment by supplying a constant voltage to the battery instead of a constant current, and find the effective condition to improve the electrochemical performance and not to have any influence on other components of the battery.
- Published
- 2017