Innovations Pile up as Eco-Friendly Car Battery Goes Mainstream
Activities related to the development of innovative rechargeable batteries have been accelerating in preparation for their practical application in the first half of the 2020s. At the back of this trend are the proliferation of electric vehicles (EVs) as environment-friendly vehicles and the widespread use of Internet of Things (IoT) devices. Recently developed are lithium-ion rechargeable batteries that adopt hardly combustible electrolyte, feature higher safety and are harmless even when they are disposed. Practical application of all-solid-state batteries, which feature quick charging and higher safety, and enable longer cruising range, has also been advancing.
Fig. 1: Transitions from lithium-ion batteries to innovative batteries
Amid global calls for the reduction of environmental load and the expansion of IoT applications, market expectations for innovative rechargeable batteries have been heightening. The Chinese government has implemented policies to promote the proliferation of EVs to prevent air pollution. Meanwhile, the State of California in the United States has certified the zero emission vehicle (ZEV) regulations, which mandate automakers that sell more than a certain number of vehicles in California to sell a certain percentage of EVs and fuel cell vehicles among its fleet. In countries in Europe, there are moves to expedite the introduction of next-generation vehicles in order to clear the emission regulations to be implemented in 2021. In Japan, toward energy savings and the reduction of carbon dioxide (CO2) emissions, the government has put up a goal to increase the ratio of EVs and other environment-friendly vehicles in new auto sales up to 30 percent by 2030. In order to achieve these goals, onboard storage batteries that power EVs, plug-in hybrid vehicles (PHVs), and fuel cell vehicles (FCVs) and achieve cruising range comparable to that of gasoline-powered vehicles, are required. The full deployment of EVs is also constraint by battery-related issues, like increase of rechargeable battery capacities, extension of batteries' charging and discharging cycles, and installation of more facilities for high-speed charging.
On the other hand, all-solid-state batteries feature high capacity, high density, and high safety, and enable quick charging. They also have long life, wide temperature range, and high degree of design freedom in terms of shape and cell. With these features, the development of all-solid-state batteries continues to advance.