Unlocking the passivation nature of the cathode–air interfacial reactions in lithium ion batteries

摘要

The green dashed lines outline the surface boundaries of NMC811. – The distinct capability of each air component in delithiating the NMC811. The upper panels are the HRTEM images of NMC 811 surface after exposure to N , O , CO , and water vapor at the gas pressure of 5 × 10  Torr and at the room temperature for 30 mins, respectively. The lower panels show the schematic drawing of Li ions evolution in the layered structure under the exposure of each corresponding gas. The label 1 and 2 in indicate the typical two steps for the formation of LiOH: the Li diffusion from bulk to surface, followed by the surface reactions. , Identification of surface reaction products by HAADF-STEM and the corresponding ABF-STEM imaging of NMC811 after prolonged exposure in water vapor. Atomistic model of LiOH on NMC substrate with the alignment of LiOH(001)//NMC(001) and LiOH[230]//NMC[1-10]. The simulated HRTEM image based on the model in . Scale bar, 2 nm , .