Search

The electronic conductivity enhanced has been extensively studied and reported in lithium iron phosph-ate (LiFePO4). However, only few existing literatures are available for researchers to enhance simultaneously the ion and electronic conductivity of LiFePO4. Herein, we disclose that the LiFePO4 is co-coated with novel GdPO4 and Carbon via a hydrothermal-assisted solid-phase method, contributing to particle size and dispersibility. What surprising is that the ionic and electronic conductivity of the material is significantly enhanced, and the interfacial side reaction is effectively inhibited between the materials and the electrolytes. The diverse proportions of the mixed coating (LiFePO4/C&xGdPO4 (x = 0, 1 wt%, 2 wt%, 3 wt%, 4 wt%)) are synthesized compared with bare LiFePO4. The experimental results suggest that LiFePO4/C&0.03GdPO4 exhibits the most excellent electrochemical performance. There is discharge capacity of 158, 148.8, 141.6, 134.9, 121.8, 104.9, and 86.7mAh/g at 0.1, 0.2, 0.5, 1, 2, 5, and 10 C rates, respectively.

In this paper, nano-scale LiFePO4/C composite was prepared by adding monocarboxylic acid (benzoic acid), dicarboxylic acid (oxalic acid) and tricarboxylic acid (citric acid) as additives in ethylene glycol. A systematic description of the impacts from the number of carboxyl groups on the morphology and electrochemical properties of LiFePO4/C composite in the ethylene glycol system was provided. And the significantly size reduction and similar morphology to uniform rice grain were observed after the surface grafting reaction of ethylene glycol with carboxylic acids on the LiFePO4/C particle surface. Furthermore, the experiments indicated regular changes in the dispersibility and electrochemical properties. The sample in which citric acid was added performed best in terms of dispersibility with the particle size of about 800 nm, and also good regarding electrochemical property with first discharge capacity of 148.13 mAh/g and coulombic efficiency of 97.97%.