Metal–organic framework‐derived LiFePO4/C composites for lithium storage: In situ construction, effective exploitation, and targeted restoration

Abstract

Abstract Hitherto, LiFePO4 (LFP) is bottlenecked by inferior electronic conductivity and sluggish Li+ diffusion, which can be resolved by cation doping, morphological engineering, carbon coating, and so forth. Among these methodologies, morphological optimization and carbon modification can warrant a stable operating voltage and prolong the cycling lifespan, which can be accessible by utilizing metal–organic frameworks as self‐sacrificing templates. Herein, we conceptualize a strategy to in‐situ construct N‐doped carbon‐coated LFP with Prussian blue analogues as the template, after which electrochemical tests extensively exploit the lithium storage capacity with 153.2 mAh g−1 after 500 cycles at 0.5 C. However, the capacity failure associated with the inevitable Li+ loss and destructed carbon layer provides sufficient room for the restoration of LFP after long‐term cycling. Motivated by this, the cell performance of LFP/C after targeted restoration using the 3,4‐dihydroxybenzonitrile dilithium salt is investigated, revealing a considerable recovered capacity due to the recuperative LFP crystal and uniform carbon layer with homogeneous N‐distribution. The computational study also supports the feasibility of N‐doped carbon layer in LFP modification. This study envisages a methodology for the performance improvement of LFP from directional fabrication to targeted recovery, providing insights into the manufacturing and reuse of LIB cathodes.

Keywords

• cathode materials
• LiFePO4/C
• metal–organic frameworks
• N‐doped carbon coating