Electrochemical batteries, lithium ones in particular, are the best option, converting stored chemical energy into electricity with high efficiency and without toxic emissions.

电化学电池，特别是锂电池，成为了最佳选择，因为它们把化学能转变为电能效率很高并且无有毒物质释放。

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The batteries have to store a lot of energy in a small, light package, scoring high in a quality known as energy density.

新型电池必须在轻小的电池组里储存大量电能，在能量密度上表现出高评分。

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In the near term, better electrodes that store more energy using less material could help, such as the silicon ones Panasonic is rolling out (Tesla to Use High-Energy Batteries from Panasonic).

在近期内，使用较少的材料、却能储存更多电能的较佳电极可能有所帮助，例如松下企业所推出硅质电极(参见“特斯拉汽车将采用松下企业的高能量电池”一文)。

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We're resigned to the fact that the constantly increasing power demands of modern gadgets will always outstrip slow increases in the energy density of batteries: however, high energy density is not the only factor that goes into making a good battery.

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For those who slept through their high-school physics classes, batteries work by converting chemical energy into electricity.

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This type of battery has an unusually high energy density, which means the units can be smaller and thus lighter for a given amount of power than traditional batteries.

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