A Robust and Scalable N-Doped Carbon Coating Strategy for the High-Performance LiFePO4 Cathode

While the stable long-cycle performance of LiFePO4 (LFP) cathodes holds significant promise for lithium-ion batteries (LiBs), their specific capacity and rate performance still fall short in market applications. In this study, we investigate surface modification of LFP using a cost-effective and highly conductive polyacrylonitrile (PAN)-induced carbon coating. Our findings indicate that 2 wt % of PAN can form a stable N–C layer on the surface of LFP particles, enhancing the Li+ storage performance. Specifically, the initial discharge capacity reaches 153.9 mAh g–1 at 0.5 C, with LFP-2 maintaining 148.8 mAh g–1 after 150 cycles, significantly outperforming their counterparts LFP-0, LFP-1, and LFP-3. Under 1 C, the LFP-2 cathode exhibits an initial discharge specific capacity of 143.2 mAh g–1 and excellent cycle stability, retaining 84.32% of its capacity after 500 cycles. Additionally, LFP-2 demonstrates stable rate performance at 0.1, 2, 4, 6, 8, and 10 C, delivering capacities of 159.4, 124.1, 110.6, 85.1, 73.0, and 62.5 mAh g–1, respectively. These results suggest that a uniform surface coating strategy could serve as an industrially scalable method for achieving a continuous carbon layer coating on other cathode materials.