The first batteries have a GWh capacity but this will increase from 3-5 GWh next year. The only downside is that sodium is quite a bit heavier than lithium and so its energy capacity is not so high. However, it is catching up. 

At the moment it can manage 160 Wh/kg energy density, and has also hinted that its next generation Na-ion cells will surpass the 200 Wh/kg threshold. Tesla's much touted affordable 4680 battery that now goes in the Model Y returned just 244 Wh/kg energy density in recent tests, the sodium-ion cells are not to be underestimated, considering the affordability of their raw materials.

The sodium-ion battery factory has been completed over the summer by Hina Battery, in partnership with the state-owned power company China Three Gorges Corporation (CTG). Two of the CTG affiliates, together with the government of Fuyang city where the factory is built, have fronted some of the funds and incentives for the sodium-ion battery research and production.

HiNa's Na-ion cells have 145 Wh/kg energy density and are good for 4,500 full charge-discharge cycles. The company's research is geared towards developing the second generation which should deliver up to 200 Wh/kg energy density and double its charge cycles.