Fluoroethylene carbonate (FEC) is an organic compound that is mainly used as an electrolyte additive for lithium-ion batteries. Ethylene carbonate derived from vinyl fluoride was introduced. The process produces a unique compound with remarkable properties that can greatly improve the performance and lifespan of rechargeable batteries. The FEC is an essential component to stabilize the interface between the Li metal anode and the electrolyte, leading to safer and more efficient operation.