包覆鳞片石墨嵌锂行为的研究

Study of lithium intercalation into coated flake graphite

采用混合后气流分散的方法制备了酚醛树脂包覆石墨,炭化后在石墨表面形成一层树脂炭包覆层。研究表明:包覆层越厚,锂离子嵌入越难。随着包覆层由0 54μm增加到1 49μm,内核石墨逐渐由一阶和二阶的混合阶石墨层间化合物过渡到二阶石墨层间化合物。鳞片石墨嵌锂时单方向、10%的巨大膨胀量和高强度树脂炭包覆层抑制膨胀,是抑制锂离子嵌入包覆石墨的主要原因。

Phenolic resin coated flake graphite was prepared by gas dispersing the phenolic resin and graphite slurry. After carbonization, resin carbon coated graphite with carbon shell-graphite core structure was obtained. With the thickness of coating layer increasing from 0.54 μm to 1.49 μm, the lithium intercalation was more difficult. And after full intercalation, the inner graphite intercalation compounds changed gradually from the mixture of stage 1 and stage 2 to only stage 2. The reason lied in the contradiction between the tremendous expansion of 10% through only one direction in inner flake graphite and the resin carbon layer restraining expansion.