Light weight, higher energy density, small volume.

轻便，高能量，体积小。

youdao

Diesel fuel has a higher energy density than gasoline, so a diesel engine gets better mileage.

柴油比汽油能量密度更高，所以柴油发动机行程更长一些。

youdao

Lithium cells provide much higher energy density than the conventional nickel-metal-hydride packs currently used in hybrids.

与当前混动汽车上使用的镍氢电池相比，锂电池具有更高的能量密度指在一定的空间或质量物质中储存能量的大小。

youdao

Without any intervention from politicians or environmentalists societies that progress have been using m ore fuels that have less carbon with higher energy density (1 kg of wood fuels a light bulb for 1 day, 1 kg of coal fuels a light bulb for 4 days, 1 kg of crude oil for 5 days, 1kg of methane for 6 days and 1 kg of uranium for over 140 years).

FORBES: Investing in Biofuels or Biofools?