Effect of Short-Chain Amine Coatings on the Performance of LiFePO4 Li-Ion Battery Cathodes

This paper probes the coating of LiFePO4 (Phostech Lithium) particles by the self-adsorbance of surfactant molecules. The presence of the short-chain amines: hexadecylamine and polyetheramine [glyceryl poly(oxypropylene)triamine] on the particles is confirmed qualitatively by X-ray photoelectron spectroscopy analysis, and the Brunauer-Emmett-Teller surface area of the amine-coated LiFePO4 decreases with increasing amounts of amine on the surface. LiFePO4 with a 1 wt % polyetheramine coating exhibits a capacity of similar to 160 mAh/g, i.e., 13% higher than could be achieved with the as-received LiFePO4. A small amount of oligomeric coating would thus appear to be capable of increasing ion transport close to the particle surface.