Stable crystal structure of Ni-rich LiNi1-x-yCoxMnyO2 (NCM) cathode materials allows high extents (>50%) of delithiation and high capacities (>190 mA h g-1). Our in operando XRD data show that further extraction of 80% Li induces drastic decrease in interplane spacing. Surprisingly, relithiation of the material occurs differently than delithiation. It is necessary to determine how Li percolate back into the structure, when the interslab distance remains substantially short. However, XRD is difficult to use for obtaining information on Li due to its high transparency to X-rays. We have investigated delithiated NCM samples using ex-situ ND. Large sample mass (3 g) and long pattern collecting time (2 h) provided sufficient data quality for Rietveld refinement on Li positions. However, ex-situ ND may suffer from material degradation during sample preparations. Thus, we have developed a novel low background in-situ ND electrochemical cell containing a large mass (4 g) of a cathode material. Currently, the existing delithiation techniques are being adopted for the developed ND cell. Then, the adopted technique will be used for the in-situ ND at the high (>80%)degrees of delithiation.