Toyota Motor Corp disclosed the framework of the all-solid battery that it aims to commercialize in early 2020s in an interview with Nikkei xTech/Nikkei Automotive.

The base of the all-solid battery is a technology to lower the internal resistance of the cell of all-solid battery. With the technology, Toyota paved the way for the commercialization of all-solid battery, which was believed to be difficult to be applied to electric vehicles (EVs) because of its low output density.

With a low output density, it is not possible to increase energy density, which is a trade-off in relation to the design of battery cell, making commercialization impossible.

With the basic technology, Toyota increased the output density (per volume) of all-solid battery to about 2.5kW/L. At the same time, it succeeded in increasing the energy density (per volume) to about 400Wh/L, which is about 100% higher than that of lithium-ion (Li-ion) batteries manufactured in about 2010.

The cell performance is much lower than that of existing advanced Li-ion batteries. However, Toyota is currently making efforts to commercialize an all-solid battery whose performance is higher than that of the advanced Li-ion batteries. The company aims to commercialize an all-solid battery based on the technology with a small production volume in early 2020s first. The establishment of volume production technology is a goal that the company plans to achieve after that.

Toyota is considering commercializing a sulfide-based all-solid battery, which is considered to have a higher ion conductivity than other solid electrolytes, in early 2020s. As positive- and negative-electrode materials, it plans to use active materials that are commonly used for existing Li-ion batteries.

Specifically, for the positive electrode, the company is considering layered oxides such as lithium cobalt oxide (LCO), lithium nickel-manganese-cobalt oxide (NMC) and lithium nickel-cobalt-aluminum oxide (NCA). For the negative electrode, it plans to use carbon-based materials, etc.

Original Japanese article