No. 789: A new battery with high storage performance (October 9, 2013)

Technology:

The 54th Battery Symposium in Japan

Each of Osaka University and Kyoto University developed a new battery called “polyvalent ion battery.” The polyvalent ion battery uses oxide materials for the positive electrode and metals like magnesium and aluminum for the negative electrode. It is free from the fear of unusual heat evolution and ignition, both of which are inherent defects of the lithium-ion battery. Because an ion can transport several electrons, it is possible to increase the battery capacity. However, because discharge and charge deteriorates the positive electrode, a polyvalent ion battery allows only for several times of discharge and charge.

Susumu Kuwabata of Osaka University developed an aluminum battery that allows for more than 100 times of discharge and charge in alliance with Kansai University. They built a positive electrode using cloth made of active carbon thread and let it absorb bromine that interferes with the reaction of discharge and charge. They plan to increase the capacity in collaboration with battery manufacturers and apply the new battery to the storage system of photovoltaic generation for housing in five years.

Yoshiharu Uchimoto of Kyoto University developed a technology to prevent the deterioration of the polyvalent battery by building the structure of the positive electrode that allows magnesium ion to go in and out easily. His research team built a trial battery of 5 cm square and found that the performance of the battery did not deteriorate even after several tens of times of discharge and charge. He plans to improve the battery to allow for quick charge and apply it to housing and electric vehicles after 2020.

The above two researchers successfully increased the number of times of discharge and charge to the practical level. Their research results are scheduled to be presented in the 54th Battery Symposium in Japan.