Enhanced interfacial reaction interface stability of Ni-rich cathode materials by fabricating dual-modified layer coating for lithium-ion batteries

Abstract Nickel-rich are considered as promising cathodes for high energy density of lithium-ion batteries (LIBs) due to their high capacity and low cost. However, the rapid capacity fading caused by interface instability and structure degradation during the charge/discharge process which lead to poor cycling performance, and seriously limited their practical application in LIBs. Herein, we report a coating modification strategy for synthesis of LiAlO2/LiF&AlF3 hybrid coating layer on LiNi0.6Co0.2Mn0.2O2 surface. In constructed this hybrid layer, the LiAlO2 with high ionic conductor could can tightly immobilize on NCM surface, and the LiF&AlF3 layer can function as an isolated layer to suppress the attack by HF. Therefore, combined with the advantages of LiAlO2/LiF&AlF3 hybrid coating layer, the structural degradation and intergranular cracks can be effective mitigated during the long-term cycling process. As a consequence, the hybrid layer modified LiNi0.6Co0.2Mn0.2O2 materials exhibit a discharge capacity of 166.8 mAh g−1 with capacity retention of 74.5% at 5 C after 300 cycles. Moreover, the rate performance was also enhanced, and deliver a discharge capacity of 155 mAh g−1 even at 10 C.