Amorphous fluorine glaze for crack-free nickel-rich layered cathode grains under electrochemical cycling

Abstract

Nickel-rich layered cathode is a potential alternative material for high energy density lithium-ion batteries, but suffers fast capacity fading due to cathode grain cracking and surface collapse. Herein, a facile fluorine glaze is proposed to modify LiNi0.8Co0.15Mn0.05O2 grain surfaces. The metal fluoride glaze prevents cathode from grain cracking and surface collapsing effectively, and further promotes lithium-ion transport. The as-protected LiNi0.8Co0.15Mn0.05O2 shows a reversible capacity of 193 mAh g−1 under the voltage range of 2.8–4.3 V, which can retain almost 100% after 400 cycles and excellent rate performance of 125 mAh g−1 at 10C, much better than pristine cathode. Moreover, typical pouch cell, using fluorine glaze modified LiNi0.8Co0.15Mn0.05O2 cathode, also harvests robust cycling performance of 87 % capacity retention after 250 cycles. Our work provides a general and simple strategy for high performance nickel-rich cathode with superior structural and chemical robustness.