Hideaki Horie

EVs and HEVs: The Need and Potential Functions of Batteries for Future Systems

There are several advantages to utilizing electric powertrains compared with conventional combustion engines for automotive applications. The first advantage is that electric devices can attain much higher energy efficiencies than internal combustion engines, which fundamentally have an upper limit on the energy conversion efficiency attributed to the second law of thermodynamics.

Capacity fade model of Lithium-ion batteries for Practical use

Lithium-ion (Li-ion) batteries are essential components for electric vehicles and smart grid systems that will become increasingly widespread in the future. However, the complexity of the capacity fade mechanism of Li-ion batteries has been a technical barrier to their practical use. This study proposes a capacity fade model composed of three factors: capacity loss, increase in internal resistance, and diffusion effect. The model derives sufficient information from battery data and conditions of use for evaluating and predicting capacity fade. The battery data includes discharge curves and electrode materials. The conditions of use are elements correlated to the three factors listed above and include the number of cycles and storage time. This paper discusses the availability of our proposed model by applying it to Li-ion battery data obtained from reference papers.