Honorary Fellow, Asahi Kasei Corporation
Professor, Graduate School of Science and Technology, Meijo University
Dr. Akira Yoshino has made significant contributions to the development of lithium ion batteries. His chief contributions are in the development of its elemental technologies, including the aluminum foil current collector for the positive electrode and the polyethylene separator, which he combined with existing LiCoO2 positive electrode materials and carbon-based anode materials to achieve a practically viable lithium ion battery capable of generating an electromotive force of 3.9V or greater.
Leading up to the realization of practical lithium ion batteries, there had been various advances in the development of elemental technologies. In 1979, Dr. Koichi Mizushima and Dr. John B. Goodenough at the University of Oxford developed the LiCoO2 positive electrode. Patents were filed by Dr. MacDiarmid of the University of Pennsylvania for the polyacetylene anode and by Dr. Hironosuke Ikeda of Sanyo Electric Co. for the graphite anode in 1980 and 1981 respectively.
At the time, promising positive electrode materials, such as combinations of metal-chalcogenide compounds and carbon anodes or LiCoO2 positive electrodes and lithium metal anodes, lacked the electromotive force for the realization of practical lithium ion batteries. By combining his original elemental technologies with existing technologies, Dr. Yoshino realized the lithium ion battery system, and this breakthrough went on to become one of the basic patents for lithium ion batteries. Having invented, developed and engineered this technology, Dr. Yoshino’s contribution has been truly immense.
Digitization, the IT revolution, and the mobile revolution centered around cell phones that arose in the early 90s would not have been possible without the advent of compact, lightweight, high capacity and long-life lithium ion batteries. Today, mobile devices have become an integral part of the social infrastructure in both developed and developing countries. More recently, lithium ion batteries have been used in hybrid, electric, and fuel-cell vehicles, contributing to the reduction of environmentally harmful emissions from transportation. Now is the time to reevaluate the potential of this technology, as its importance continues to grow in anticipation of further application of lithium ion batteries, including cascading, to resolve the instability in the supply of natural energy as a countermeasure to global warming. Dr. Yoshino’s accomplishments are especially momentous, for they have become the foundation of today’s lithium ion battery technology and industry.
It is for these significant contributions to the advancement of science and technology through innovative breakthroughs in the development of lithium ion batteries that Dr. Akira Yoshino is deemed most eminently deserving of the 2018 Japan Prize given to honor contributions in the field of "Resources, Energy, Environment and Social Infrastructure."