This proposal describes a continuous experiment for a muSR study of a Li-ion battery cathode sheet. In the previous experiments, we used powder samples peeled off from a cathode sheet in a test battery. In May, we have attempted to measure muSR spectra for the cathode sheet itself at ISIS, in order to perform in situ experiment in the near future. As a result, we have just observed Li-ion diffusive nature in a charged cathode sheet, where Lix(Ni0.75Co0.15Al0.05Mg0.05)O2 (LixNO, Li content; x=0-1) is coated as active materials with carbon and binder. We wish to clarify the x dependence of Li diffusive nature in LixNO in wider x range. Such information is very useful to determine the optimal charging condition for the cathode.