Hollow submicrospheres of trimetallic selenides for high-capacity lithium and sodium ion batteries

Highly conductive metal selenides have drawn increasing attention in the field of energy storage. Unfortunately, their application is severely limited by the inferior capacity contribution as well as unsatisfactory cycling stability. Here, we propose a simple and practical way to prepare hollow nickel–cobalt–manganese selenides (NCMSe) submicrospheres. The NCMSe submicrospheres exhibit rich redox reactions during the reaction process into which much more alkali metal ions can be inserted, leading to high reversible capacity and their hollow structure facilitates the contact between the active material and electrolyte to accelerate the redox kinetics. Benefiting from these features, the hollow NCMSe submicrospheres show superior Li–storage capacity (1600 mAh g⁻¹ after 1000 cycles at 2 A g⁻¹) and Na–storage capacity (695 mAh g⁻¹ after 200 cycles at 0.1 A g⁻¹). This work offers a novel insight to the remarkable electrochemical performance anode materials for both lithium and sodium ion batteries.