Mechanisms responsible for two possible electrochemical reactions in Li1.2Ni0.13Mn0.54Co0.13O2 used for lithium ion batteries

dQ/dV curves of Li1.2Ni0.13Mn0.54Co0.13O2 within potential range of 2.5-4.6 V (vs. Li/Li+) in third, sixth, and ninth cycles. Two phases, namely, Li2MnO3-like and LiNi0.33Mn0.33Co0.33O2-like, exist in Li1.2Ni0.13Mn0.54Co0.13O2. Li2MnO3-like, LiNi0.33Mn0.33Co0.33O2-like, and Li2MnO3-like phases mainly contribute to the charge reaction in the low, middle, and high state of charge (SOC) ranges. In contrast, the Li2MnO3-like and LiNi0.33Mn0.33Co0.33O2-like phases mainly contribute to the discharge reaction in the low and high SOC ranges. The potential shift during the cycling of Li1.2Ni0.13Mn0.54Co0.13O2 is mainly attributed to the Li2MnO3-like phase.158