" It's cheap, it's high energy density, so it seems to be a no-brainer, " Ehmes said.

“它价格便宜，而且能量密度高，所以看起来很简单”。

This, too, demands a technological leap towards new materials, higher energy density, and better storage.

这也需要在新材料、更高能量密度和更好的存储方面实现技术飞跃。

Lipo batteries have a high energy density, but a low weight and they're very robust.

锂聚合物电池具有高能量密度，但重量轻， 而且非常坚固。

But chemicals can hold a lot of energy, so batteries have high energy density (the amount of energy they can contain, again per unit weight).

但是化学物质可以储存很多能量，所以电池有很高的能量密度（每单位重量可以包含的能量）。