But other companies were developing increasingly efficient batteries to power a new wave of portable electronics.

但其他公司正在开发越来越高效的电池为新蜂拥而至的便携式电子产品供电。

Meaning it's better suited for things like electric cars and portable electronics. Not power grids that stay still.

这意味着它更适合电动汽车和便携式电子产品。而不是静止不动的电网。