Electrochemical Performance of Carbon Modified LiNiPO$_{4}$ as Li-Ion Battery Cathode: A Combined Experimental and Theoretical Study

This study demonstrates the synthesis of olivine LiNiPO4and carbon modified LiNiPO4(LNP/C-composites) cathode materials foruse in lithium-ion batteries (LIBs) synthesized via non aqueous sol-gel process. The LNP/C-composites were fabricated throughhigh energy ball-milling of LiNiPO4with different weight ratios of conductive carbon black. The electrochemical performance ofLiNiPO4has been considerably improved by modifying the material with conductive carbon black which enhanced cathodeperformance as thoroughly studied by electrochemical analysis. Discharge capacities of LNP/C-composite cathodes with 25 wt%carbon were 175 mAh g−1, 150 mAh g−1and 125 mAh g−1with corresponding capacity retention of 82.7%, 84.1% and 82.2%after 100 cycles at 0.05C, 0.1C and 1C rates, respectively. High-temperature electrochemical impedance spectra correspond todecreased charge transfer resistance with increased electronic conductivity and minimum cell polarization for the LNP/C powders.Additionally, the inflow of lithium-ionflux in cathode particle was simulated by using phase-field modeling indicating thecoexistence of Li-poor and Li-rich phases during charging and discharging processes. ... mehrThefindings are significant for thedevelopment of optimal battery electrode materials as the methodology and insights used are readily transferable to other ion-insertion based electrodes