NEGATIVE ELECTRODE THIN FILM FOR LITHIUM SECONDARY BATTERY AND PREPARATION METHOD THEREOF

摘要

PURPOSE: A negative electrode thin film for a lithium secondary battery, its preparation method and a lithium secondary battery employing the negative electrode thin film are provided, to improve the cycle characteristic remarkably by inhibiting the expansion and contraction of tin generated during the charging and discharging process and to enhance of the chemical and mechanical stabilities of the interface between a battery and an electrolyte and the lifetime of a battery. CONSTITUTION: The negative electrode thin film comprises a current collector(20), and a negative electrode active material layer formed on the current collector(20), wherein the negative electrode active material layer comprises a compound of Sn and Ni. Preferably the compound of Sn and Ni is Ni3Sn4. The method comprises the step of evaporation-depositing Ni3Sn4 by the electron beam evaporation and/or the ion beam assisted deposition by using a Sn-Ni source material. Preferably the lithium secondary battery is a thin film-shaped one.