Controllable organic/inorganic composite film enables improved long-term and high-temperature storage performance of lithium primary battery

Though lithium primary battery has been widely used, high temperature and long-term storage still possibly cause its failure because of the active lithium anode, which continuously reacts with electrolyte, forms an unstable solid electrolyte interface and leads to the degradation of battery performance. In this work, a novel organic-inorganic composite protecting film composed of well-dispersed inorganic lithium nitride (Li3N) among poly (propylene carbonate) (PPC) organic matrix is controllably fabricated on the Li anode by spin coating, to enhance interfacial compatibility and stability. The composite film exhibits superior ionic conductivity of 3.57 × 10−4 S cm−1, and the Li-CFx battery with composite film delivers an excellent specific discharge capacity of 940 mAh g−1 at 0.1 C, and excellent rate capacity of 492 mAh g−1 even at 8 C. After storage at room temperature and 55°C for 60 days, the battery can still release high specific capacities of 867 and 536 mAh g−1. With the assistance of composite film, a stable Li3N/LiF-rich SEI is formed on the Li anode and LiF-rich CEI is generated on the CFx cathode, ensuring long-term and high-temperature storage stability of Li-CFx battery. This study demonstrates a facile organic/inorganic composite film protecting strategy to achieve high-performance lithium battery.