A stable Li-deficient oxide as high-performance cathode for advanced lithium-ion batteries

Abstract

Monodisperse Li-deficient Li_0.35Ni_0.2Co_0.1Mn_0.7O_2−x spinel single crystals have been prepared for the first time. The Li-deficient oxide surprisingly delivers large reversible capacity (251.3 mA h g⁻¹), outstanding cycle life and low median-voltage of 2.7 V in the range of 2.0–4.9 V. Importantly, high median-voltage (4.4 V) and superior rate capability are also obtained from 3.0 to 5.0 V. These results indicate that high-energy or high-power density can be achieved by controlling discharge cut-off voltage.