Enhancement of Li2ZrO3 Modification of the Cycle Life of N/S-Doped LiMn0.5Fe0.5PO4/C Composite Cathodes for Lithium Ion Batteries

LiMn 0.5 Fe 0.5 PO 4 cathodes have a high energy density but a poor rate and poor cycling performance. To this end, a series of N/S-doped LiMn 0.5 Fe 0.5 PO 4 /C composite cathodes modified with different contents of Li 2 ZrO 3 were prepared by a solvothermal synthesis combined with calcination. The microstructure, chemical composition, and electrochemical properties are analyzed. Li 2 ZrO 3 adsorbed on the LiMn 0.5 Fe 0.5 PO 4 primary particles’ surface in an amorphous state and on spherical particles (5–10 nm). The cycling life and rate performance of the cathodes are improved by the modification of a moderate amount of Li 2 ZrO 3 . The LMFP/NS-C/LZO1 shows available capacities of 166.8 and 118.9 mAh·g –1 at 0.1 and 5 C, respectively. The LMFP/NS-C/LZO1 shows no capacity loss after 100 cycles of charging/discharging (1 C), and still has a high capacity retention of 92.0% after 1000 cycles of charging/discharging (5 C). The excellent cycling performance of the LMFP/NS-C/LZO1 can be attributed to the improvement of the cathode microstructure and the electrochemical kinetics and the inhibition of Mn 2+ dissolution by the moderate Li 2 ZrO 3 modification.