Multi-Electron Reaction-Boosted High Energy Density Batteries: Material and System Innovation

The continuous development of the global energy structure transformation has put forward higher demands upon the development of batteries. The improvements of the energy density have become one of the important indicators and hot topic for novel secondary batteries. The energy density of existing lithium-ion battery has encountered a bottleneck due to the limitations of material and systems. Herein, this paper introduces the concept and development of multi-electron reaction materials over the past twenty years. Guided by the multi-electron reaction, light weight electrode and multi-ion effect, current development strategies and future trends of high-energy-density batteries are highlighted from the perspective of materials and structure system innovation. Typical cathode and anode materials with the multi-electron reactions are summarized from cation-redox to anion-redox, from intercalation-type to alloying-type, and from liquid systems to solid-state lithium batteries. The properties of the typical materials and their engineering prospects are comprehensively discussed, and additionally, the application potential and the main challenges currently encountered by solid-state batteries are also introduced. Finally, this paper gives a comprehensive outlook on the development of high-energy-density batteries.