Reviews on the Japanese Patent Applications Regarding Nickel/Metal Hydride Batteries

The Japanese Patent Applications filed on the topic of nickel/metal hydride (Ni/MH) batteries have been reviewed. Patent applications filed by the top nine battery manufacturers (Matsushita, Sanyo, Hitachi Maxell, Yuasa, Toshiba, FDK, Furukawa, Japan Storage, and Shin- kobe), five component suppliers (Tanaka, Mitsui, Santoku, Japan Metals & Chemicals Co. (JMC), and Shin- Etsu), and three research institutes (Industrial Research Institute (ISI), Agency of Industrial Science and Technology (AIST), and Toyota R & D) were chosen as the main subjects for this review, based on their production volume and contribution to the field. By reviewing these patent applications, we can have a clear picture of the technology development in the Japanese battery industry. These patent applications also provide insights, know- how, and future directions for engineers and scientists working in the rechargeable battery field.