In-situ study of charge and discharge of Ni-MH battery using the combined method of electrochemistry and microcalorimetry

An apparatus to study the battery system has been set up. The thermal effec ts of charge and discharge of Ni-MH batteries have been studied. The calori metric measurements indicate that the net heat dissipation during charging is larger than that during discharging. It is observed that the ratio of he at dissipation to charging energy varies with charging capacity, and almost 90 percent of charging energy is lost as heat dissipation near the end of the charging process at 97.7 mA. A jump of thermal curve near the end of di scharge due to a secondary electrode reaction has been observed.