Primearth EV Energy, an electric vehicle battery joint venture between Toyota Motor and Panasonic, plans to build a fourth factory in China for electric vehicle batteries, according to local reports.

Primearth aims to complete construction of the plant in Beijing by 2021 with an initial annual capacity of 100,000 nickel metal hydride battery (NiMH) battery packs for hybrid vehicles produced by Toyota, the reports suggest.

This would raise the company's capacity in China to 400,000 battery packs per year. 

Primearth, which is 80.5% controlled by Toyota, already has a NiMH battery plant in China, in Jiangsu province, and a further two currently under construction in the country which are scheduled to go into production this year.

Toyota expects demand for plug-in hybrid vehicles in China to continue to rise, and possibly outperform electric vehicles, driven by new regulations to promote purchases of low consumption, low emission vehicles.

Sales of new energy passenger vehicles, comprising mainly electric and hybrid models, rose by 53.7% to 645,000 units in the first seven month of 2019.