Na-ion mobility in P2-type NaMgNiMnO (0 x 0.07) from electrochemical and muon spin relaxation studies

電気化学測定及びミュオンスピン緩和測定により求めたP2型NaMgNiMnO (0 x 0.07)におけるNa移動度

Ma, L. A.*; 杉山 純; 他10名*

Ma, L. A.*; Sugiyama, Jun; 10 of others*

Sodium transition metal oxides with a layered structure are one of the most widely studied cathode materials for Na ion batteries. Since the mobility of Na in such cathode materials is a key factor that governs the performance of material, electrochemical and muon spin rotation and relaxation techniques are here used to reveal the Na ion mobility in a P2-type P2-type NaMgNiMnO (x = 0, 0.02, 0.05 and 0.07) cathode material. Combining electrochemical techniques such as galvanostatic cycling, cyclic voltammetry with SR, we have successfully extracted both self-diffusion and chemical-diffusion under a potential gradient, which are essential to understand the electrode material from an atomic-scale viewpoint. The results indicate that a small amount of Mg substitution has strong effects on the cycling performance and the Na mobility.