储锂硅材料的ESR谱研究

采用了电化学方法制备储锂硅材料，并用电子自旋共振(ESR)方法进行研究. 实验结果表明， 储锂前的硅ESR行为符合居里自旋的ESR特征， ESR信号主要来源于硅材料中的晶格缺陷、 表面悬空键等局域化自旋中心. 储锂后硅材料中产生了泡利自旋，居里自旋的强度比储锂前增大2～3倍. 此外，对硅和储锂硅ESR谱线的g因子和ΔH_pp随温度的变化情况也进行了分析. 硅材料电化学储锂时，与锂离子中和的电子主要参与形成Li-Si共价键，对ESR信号贡献很小.

An ESR Study of Lithium-stored Silicon

In this paper, lithium stored silicon were prepared with the electrochemical reaction method. The electron spin resonance (ESR) signals of silicon and lithium-stored silicon were measured. The ESR intensity of silicon showed a linear change with the reciprocal of the temperature, indicative of the presence of Curie spins, which may come from localized spin centers, such as crystal defects and hanging bonds on the surface. In lithium-stored silicon, however, both Pauli spins and Curie spins were shown to be present. The amplitude of integrated ESR signals owing to Curie spins in lithium-stored silicon was 2~3 times higher than that in silicon. The effects of temperature on the g factor and line width (ΔH_pp) of the ESR signals were also investigated. It could be concluded that when lithium ion reacts with silicon in the electrochemical reaction, compensating electrons from the external circuit mostly took part in forming the covalent bonds between Li and Si, and contributed little to the ESR intensity.