Easily Obtaining Excellent Performance High‐voltage LiCoO₂ via Pr₆O₁₁ Modification

Abstract

Developing an effective method to synthesize high‐performance high‐voltage LiCoO 2 is essential for its industrialization in lithium batteries (LIBs). This work proposes a simple mass‐produced strategy for the first time, that is, negative temperature coefficient thermosensitive Pr 6 O 11 nanoparticles are uniformly modified on LiCoO 2 to prepare LiCoO 2 @Pr 6 O 11 (LCO@PrO) via a liquid‐phase mixing combined with annealing method. Tested at 274 mA g −1 , the modified LCO@PrO electrodes deliver excellent 4.5 V high‐voltage cycling performance with capacity retention ratios of 90.8% and 80.5% at 25 and 60 °C, being much larger than those of 22.8% and 63.2% for bare LCO electrodes. Several effective strategies were used to clearly unveil the performance enhancement mechanism induced by Pr 6 O 11 modification. It is discovered that Pr 6 O 11 can improve interface compatibility, exhibit improved conductivity at elevated temperature, thus enhance the Li + diffusion kinetics, and suppress the phase transformation of LCO and its resulting mechanical stresses. The 450 mAh LCO@PrO‖graphite pouch cells show excellent LIB performance and improved thermal safety characteristics. Importantly, the energy density of such pouch cell was increased even by ~42% at 5 C. This extremely convenient technology is feasible for producing high‐energy density LIBs with negligible cost increase, undoubtedly providing important academic inspiration for industrialization.