NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, NEGATIVE ELECTRODE FOR LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY

• Main Authors: IYAMA YOSHIMI, HABA EISUKE, HONBO HIDETOSHI, SUGA KEITA, YASUDA AKIRA
• Format: Patent
• Language: English; Japanese
• Published: 23.12.2021
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

To provide a negative electrode material for a lithium ion secondary battery in which a long life and high efficiency lithium ion secondary battery can be obtained as compared with a case where a conventional silicon is used although a silicon having high electric capacity is used as compared with a case where conventional graphite is used as an electrode active material, a negative electrode for a lithium ion secondary battery including the negative electrode material, and a lithium ion secondary battery including the negative electrode.SOLUTION: A negative electrode material for a lithium ion secondary battery includes a particle containing silicon and lithium silicate, a carbon present on at least a part of the surface of the particle, and a phosphate compound present on at least a part of the outermost surface of the particle.SELECTED DRAWING: Figure 1 【課題】負極活物質として従来の黒鉛を用いた場合と比較して高い電気容量を持つシリコンを用いながらも、従来のシリコンを利用した場合と比較して長寿命かつ高効率のリチウムイオン二次電池が得られる、リチウムイオン二次電池用負極材、該負極材を含有するリチウムイオン二次電池用負極、及び該負極を備えるリチウムイオン二次電池を提供する。【解決手段】リチウムイオン二次電池用負極材は、シリコン及びリチウムシリケートを含有する粒子；前記粒子の表面の少なくとも一部に存在する炭素；及び、前記粒子の最表面の少なくとも一部に存在するリン酸化合物、を有する。【選択図】図１