Electrochemically Engineering a Single-Crystal Nickel-Rich Layered Cathode

Abstract

Nickel-rich layered electrode material has been attracting significant attention owing to its high specific capacity as a cathode for lithium-ion batteries. Generally, the high-nickel ternary precursors obtained by traditional coprecipitation methods are micron-scale. In this work, the submicrometer single-crystal LiNi0.8Co0.1Mn0.1O2 (NCM) cathode is efficiently prepared by electrochemically anodic oxidation followed by a molten-salt-assisted reaction without the need of extreme alkaline environments and complex processes. More importantly, when prepared under optimal voltage (10 V), single-crystal NCM exhibits a moderate particle size (∼250 nm) and strong metal–oxygen bonds due to reasonable and balanced crystal nucleation/growth rate, which are conducive to greatly enhancing the Li+ diffusion kinetics and structure stability. Given that a good discharge capacity of 205.7 mAh g–1 at 0.1 C (1 C = 200 mAh g–1) and a superior capacity retention of 87.7% after 180 cycles at 1 C are obtained based on the NCM electrode, this strategy is effective and flexible for developing a submicrometer single-crystal nickel-rich layered cathode. Besides, it can be adopted to elevate the performance and utilization of nickel-rich cathode materials.

Perspective on the Preparation Methods of Single Crystalline High Nickel Oxide Cathode Materials

“…Similar to sodium salts, lithium salts have also been widely utilized as flux agents for lowering the melting point of reactants, such as Li 2 MoO 4 , [62] LiCl, [63][64][65] LiNO 3 , [66][67][68] Li 2 O 2 [69] and Li 2 SO 4 . [70][71][72][73] For instance, Li 2 MoO 4 , possessing a melting point of 704 °C, has been utilized as a flux agent in the preparation of SC-NCM111.…”