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.
For most batteries, there are active and inactive materials on both the anode and cathode sides of the cell. There are two main ways to maximize energy density – 1) use active materials that can store more energy; 2) increase the percentage of active material in the cell compared to its inactive materials. Anode Active Materials
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.
This is the calculation formula of energy density of lithium secondary batteries: Energy density (Wh kg −1) = Q × V M. Where M is the total mass of the battery, V is the working voltage of the positive electrode material, and Q is the capacity of the battery.
The electrode material determines the volume energy density of the battery, so the volume energy density of the battery is forced to increase under the condition that the battery material system and volume are unchanged, which is bound to use thinner separator materials [, , ].
Using composite cathode materials without binder and conductive agent can increase the quality of the active substance of the battery by 5 % ~ 10 %, the energy density of the battery will be improved accordingly when the total mass of the battery is unchanged.