Recent progress in rechargeable nickel metal hydride and lithium-ion miniature rechargeable batteries

VARTA is searching for alternative battery solutions for memory back-up and bridging applications, and for this, it is developing nickel/metal hydride and lithium-ion button cells. Presented are the results on different sizes and forms of lithium-ion cells (621, 1216 and 2025) containing different e lectrode materials and shapes. Presently, the most favoured cathode materia l is lithiated manganese dioxide. The electrodes are made from both solid a nd porous materials and, together with an organic electrolyte, result in a cell system with a voltage level of approximately three. Included are resul ts, both from these lithium-ion cells, and also from ones using the nickel/ metal hydride system. (C) 1999 Elsevier Science S.A. All rights reserved.