AlF3包覆天然石墨负极材料的制备及其电化学性能

以天然石墨为原料,通过机械高速分散设备将天然石墨和Al F3在液相介质中充分混合,混合液喷雾干燥后获得颗粒形态均匀分散的Al F3包覆天然石墨(NG)复合负极材料(AF/NG)。一方面Al F3包覆层有助于在天然石墨表面形成稳定的SEI膜,提升材料的循环稳定性;另一方面Al F3的引入改善了锂离子在天然石墨内外的迁移与扩散,提升复合材料的倍率性能,0.5C倍率下放电比容量达到278 m Ah·g-1,同等倍率下比未包覆Al F3样品提高了78 m Ah·g-1。合成工艺简单易管控,适合规模化商业生产。

Preparation and Characterization of AlF3 Coated Natural Graphite Anode Materials

AlF₃ coated Natural graphite composite (AF/NG) was synthesized by high speed mechanical dispersion and spray drying with the natural graphite as raw material. On the one hand, a more stable SEI film can be formed with the help of AlF₃, which promoting the cycle performance. on the other hand, the AlF₃ can promote the diffusion of lithium ions between the particles, which is benefit to the rate capability. AF/NG delivered a reversible capacity more than 278 mAh·g^-1 at 0.5C, with a capacity of 78 mAh·g^-1 higher than the uncoated sample (NG). The synthetic process is easy to control which is suitable for large-scale commercial production.