Fulvic acid-derived N, S co-doped carbon coating enables superior rate capability in Mn0.5Ti2(PO4)3 anodes

N, S co-doped carbon coated 3D porous Mn 0.5 Ti 2 (PO 4 ) 3 was fabricated via fulvic acid pyrolysis. • The carbon layer synergistically enhances electronic conductivity and Li + diffusion kinetics. • The designed composite anode revealed outstanding rate capability. NASICON-structured Mn 0.5 Ti 2 (PO 4 ) 3 (MTP) has emerged as a competitive anode candidate for lithium-ion batteries (LIBs), benefiting from its abundant lattice vacancies, robust structural integrity, and suitable operating voltage. Nevertheless, the practical scalability is constrained by intrinsically low electronic conductivity. Herein, fulvic acid (FA) is employed as a carbon precursor to composite with MTP via high-temperature carbonization, aiming to optimize the electrochemical performance of MTP. Electrochemical tests reveal that the composite with FA/MTP weight ratio of 0.30 carbonized at 800℃ achieves enhanced cycling stability and rate capability, delivering lithiation capacities of 391.4 and 198.9 mAh g −1 at 0.1 and 1.6 A g −1 , respectively. The superior performance is attributed to the formation of uniform N, S co-doped carbon coating layer derived from in-situ carbonization of FA. N, S co-doping not only facilitates rapid electron transport and buffers volume changes during repeated lithiation/delithiation but also introduces additional active sites for lithium storage. Simultaneously, the incorporation of a co-doped carbon layer on MTP improves the binding affinity with MTP, thereby conferring outstanding structural durability and electrical conductivity of the composite. This work provides a simple and effective strategy for utilizing natural biomass derivatives to improve the electrochemical performance of polyanionic compounds for advanced LIB anodes. Download: Download high-res image (150KB) Download: Download full-size image