The breakthrough discoveries of John Bannister Goodenough, Rachid Yazami, and Akira Yoshino were critical to the development of rechargeable lithium-ion battery technology that has impacted consumer electronics and advanced the performance of electric vehicles. Dr. Goodenough demonstrated a rechargeable cell using lithium cobalt oxide as the positive electrode in 1979 while working at Oxford University. This provided the positive electrode material that would eventually make the lithium-ion battery possible. Goodenough's work showed, with lithium cobalt oxide, that more stable and easy-to-handle negative-electrode materials could be used if assembled in the discharged state. This ultimately opened a new range of possibilities for rechargeable battery systems. Dr. Yazami demonstrated that lithium ions could be inserted electrochemically into graphite using a solid electrolyte in 1980, working with the National Polytechnic Institute of Grenoble and the National Center for Scientific Research (CNRS). Until Dr. Yazami’s innovation, organic electrolytes would decompose in graphite during charging, which was a roadblock to using graphite for the negative electrode. Dr. Yazami’s work paved the way for the graphite negative electrode found in the modern high-capacity lithium-ion battery. Dr. Yoshino filed the first basic patent for the lithium-ion battery in 1985. Working for Asahi Kasei Corporation in Japan, he incorporated lithium cobalt for the positive electrode and a carbonaceous material for the negative electrode. He developed an aluminum foil current collector, and his functional separator and positive temperature coefficient device greatly improved safety compared to other batteries. He also established the coil-wound structure inherent to all lithium-ion batteries. In 1992, Asahi Kasei released the first commercial lithium-ion battery. In 2012 Dr. Yoshino was awarded the IEEE Medal for Environmental and Safety Technologies, along with Goodenough and Yazami,“For developing the lithium-ion battery, which enables significant fuel conservation and reduced emissions as power storage for electric vehicles and for smartgrids incorporating renewables.”
An Asahi Kasei Fellow and president of the Lithium Ion Battery Technology and Evaluation Center, Dr. Yoshino is currently general manager of the Yoshino Laboratory at Asahi Kasei Corporation, Shizuoka, Japan.