Abstract: Increasing energy density of battery will dramatically extend the driving range of electric vehicles. "Strategic Priority Research Program" of the Chinese Academy of Sciences was initiated at the November 15, 2013. In this program, the lithium-ion battery of the 3rd generation, solid-state metallic lithium battery, lithium-sulphur battery and lithium-air battery have been investigated. The mass and volume energy density of 24 A·h Li-ion single cell, with nano-silicon carbon material as negative electrode and lithium-rich material as positive electrode is achieved as 374 W·h/kg and 577 W·h/L, respectively. The energy density of 8 A·h solid lithium battery using the polymer solid electrolyte at 60 ℃ is 240 W·h/kg, while the energy density of solid-state lithium battery based on the inorganic ceramic solid electrolyte is also 240 W·h/kg. The energy density of 37 A·h lithium-sulphur battery reaches 566 W·h/kg at room temperature and 616 W·h/kg at 50 ℃. The energy density of 5 A·h lithium-air battery is 526 W·h/kg. However, these batteries are still far away from practical applications in view of satisfying all required performances. Further comprehensive researches on fundamental science and key technology are needed. In addition, the increase of the energy density of batteries will also increase the safety concerns. Therefore, all lithium batteries containing solid electrolytes could become the final solutions for EV batteries.

Key words: lithium ion battery, solid state lithium battery, lithium-sulphur battery, lithium-air battery, high energy density, EV