Lithium ion secondary batteries are widely used in small portable devices such as mobile phones. Research
and development of lithium ion batteries for use in automobiles and larger machines is an active field. To
develop lithium ion secondary batteries with high capacity, high stability and long life, it is essential to evaluate
the stability of the positive electrode material during the charge/discharge process. Operando X-ray diffraction
measurements using an attachment that reproduces the charge/discharge environment and a 2D detector
that can perform high-speed measurements enables detailed observation of crystal phase changes while a
battery is in use, making it suitable for studying battery performance and life.