Strategies toward the development of high-energy-density lithium batteries

At present, the energy density of the mainstream lithium iron phosphate battery and ternary lithium battery is between 200 and 300 Wh kg−1 or even <200 Wh kg−1, which can hardly meet the continuous requirements of electronic products and large mobile electrical equipment for small size, light weight and large capacity of the battery. In order to achieve high energy density batteries, researchers have tried to develop electrode materials with higher energy density or modify existing electrode materials, improve the design of lithium batteries and develop new electrochemical energy systems, such as lithium air, lithium sulfur batteries, etc. Here, we analyze the influence of the existing chemical system and structure of lithium-ion battery on the energy density of lithium-ion battery, and summarizes the methods of improving the energy density of lithium-ion battery in the aspects of material preparation and battery structure design. Strategies such as improving the active material of the cathode, improving the specific capacity of the cathode/anode material, developing lithium metal anode/anode-free lithium batteries, using solid-state electrolytes and developing new energy storage systems have been used in the research of improving the energy density of lithium batteries. However, due to a number of difficulties, these high energy density batteries are still in the experimental stage, and further study is needed to improve their practical applicability.