Electrochemical performance of nano-LiFePO4 embedded ordered mesoporous nitrogenous carbon composite as cathode material for Li-ion battery applications

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2019-09, Vol.848, p.113242, Article 113242
• Main Authors: Khan, Sourav, Raj, Rayappan P., Mohan, Talla V.R., Bhuvaneswari, Subramani, Varadaraju, Upadhyayula V., Selvam, Parasuraman
• Format: Article
• Language: English
• Subjects: Carbon; CMK-3; Composite cathode; Composite materials; Diffusion coefficient; Electrochemical analysis; Electrode materials; Ion diffusion; LFP/carbon; Li-ion battery; LiFePO4; Lithium; Lithium-ion batteries; MNC-31; Nanoparticles; Nitrogen
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2019.113242

We report here the preparation and electrochemical characterization of nano-sized LiFePO4, starting from Fe(III) precursor, embedded in ordered mesoporous nitrogenous carbon (LFP/MNC-31). For comparison, LFP nanoparticles embedded in nitrogen-free ordered mesoporous carbon (LFP/CMK-3) was also prepared and studied. Both these composites were characterized using XRD, FT-Raman, TEM, SEM and nitrogen sorption studies prior to electrochemical testing. The ordered and mesoporous nature of the carbon in the composites was established by small-angle XRD and BET isotherms. Reitveld refined XRD data reveals single phase formation of LFP with good crystallinity. TEM studies show that the LFP nanoparticles are embedded in the mesopores of the carbon matrix. Electrochemical studies in half-cell mode (vs. Li+/Li) reveal that the Li-ion diffusion coefficient values in the composites are remarkably higher (6–7 orders of magnitude) compared to pristine LFP. Furthermore, the LFP/MNC-31 composite shows relatively better electrochemical properties in terms of specific capacity, rate capability and cyclic stability vis-à-vis LFP/CMK-3 highlighting the importance of nitrogen doping in the carbon matrix in enhancing the electrochemical performance. [Display omitted] •Facile synthesis of novel nano-LiFePO4 embedded nitrogen-containing ordered mesoporous carbon composite cathode.•High surface area and large pore size of the ordered mesoporous carbon in the composite cathode•Significantly enhanced Li-ion diffusion kinetics•Contiguous carbon network structure facilitating electronic conductivity•Nitrogen doping in the carbon matrix enhances electrochemical performance of the composite cathode.