Further Improving Coulombic Efficiency and Discharge Capacity in LiNiO₂ Material by Activating Sluggish ∼3.5 V Discharge Reaction

The electrochemical activity of LiNiO2 at the initial cycle and factors affecting its were understood. Even though can achieve almost theoretical charge capacity, it cannot deliver discharge capacity that would result in low 1st Coulombic efficiency (CE). For different upper cut-off voltages 4.3 4.1 V, CE barely increases. Given H2-H3 phase transition occurs ∼4.2 is not caused by this but a additional 3.5 V reaction, which kinetically limited thereby activated even reasonable current density. We found out several transitions during charge/discharge affect reaction. Under galvanostatic intermittent titration technique (GITT) conditions, ∼250 mAh/g 100% with voltage fully activating Using neutron diffraction 6Li nuclear magnetic resonance (NMR) measurements, sluggish kinetics reaction be ascribed to difficult insertion Li end because accompanied rearrangement cations or local structure change structure. To high voltage, should improved. finding understanding underlying mechanism will stimulate further research on high-capacity Ni-rich layered materials for high-performance Li-ion batteries.