Copper Nitrate Enables High-performance Lithium-ion Batteries at Low Temperature

Lithium-ion batteries (LIBs) have dominated the market for electrochemical energy storage owing to their high energy density and extraordinary cycle life. However, the similar potentials of Li⁺ intercalation and Li plating result in severe capacity loss and dendrite growth on graphite anodes under extreme operating conditions, which significantly limits their applications. In this work, under the guidance of density functional theory (DFT) calculations, copper nitrate (Cu(NO3)2), a cheap and functional inorganic additive, was demonstrated a good capability to increase the potential gap by 39 mV at room temperature and as high as 67 mV at -20°C. Moreover, the rate performance was improved significantly due to the formation of a Li3N-enriched interface. As a result, the LiNi0.8Mn0.1Co0.1O2||graphite pouch cells deliver higher capacity and better cycle stability at low temperature. This technology contributes to facilitating the adjustment of the charge and discharge protocol, allowing LIBs to perform better under extreme conditions.