LITHIUM ION SECONDARY BATTERY, POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, AND METHOD OF PRODUCING POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM ION SECONDARY BATTERY

PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery capable of ensuring safety while suppressing a decrease in battery characteristics, a positive electrode active material for a lithium ion secondary battery, and a method of producing a positive electrode active material for a lithium ion secondary battery.SOLUTION: A positive electrode active material for a lithium ion secondary battery is used for a positive electrode of a lithium ion secondary battery, and has a hollow structure. A positive electrode active material 10 of a lithium ion secondary battery includes a shell part 101, a hollow part 102 at the inside of the shell part 101, and a communication hole 110 opening to the shell part 101 and communicating between the outside of the shell part 101 and the hollow part 102. In the hollow part 102, a microcapsule 50 is arranged, which expands at temperatures of equal to or more than a predetermined temperature higher than an ordinary temperature and destroys the shell part 101.SELECTED DRAWING: Figure 3 【課題】電池特性の低下を抑えつつ、安全性を確保することのできるリチウムイオン二次電池、及び、リチウムイオン二次電池用正極活物質、及び、リチウムイオン二次電池用正極活物質の製造方法を提供する。【解決手段】リチウムイオン二次電池用正極活物質は、リチウムイオン二次電池の正極に用いられ、中空構造を有する。リチウムイオン二次電池の正極活物質１０は、殻部１０１と、殻部１０１の内部の中空部１０２と、殻部１０１に開口し、殻部１０１の外部と中空部１０２とを連通させる連通孔１１０とを備えるとともに、中空部１０２には、常温よりも高い温度である所定の温度以上になると膨張して殻部１０１を破壊するマイクロカプセル５０が配置されている。【選択図】図３