Superior rate performance and structural evolution of O3-type layered NaCrO2 for sodium ion batteries at high temperatures

Emerging Chemistry for Wide-Temperature Sodium-Ion Batteries

“…When Na + is extracted from the cathode material and embedded in the anode material via the electrolyte during the charging process of SIBs, TM ions in the crystalline cathode material will act as the redox reaction centers to provide charge compensation for the charge balance of the material. However, the TM dissolution caused by the attack of acidic species presenting in the electrolytes such as hydrogen fluoride (HF) is one of the important manifestations of HT failure of SIBs. , In this case, the battery will face capacity fading, complex phase transition, and even safety issues during long-term cycling. − As demonstrated in Figure a, the TM ions will go through a dissolution–migration–deposition process . The dissolved TM ions will migrate from the cathode to the anode via the electrolyte, and then they may be deposited and accumulated on the anode driven by the concentration gradient and electric field force.…”