Fan-shape Mn-doped CoO/C microspheres for high lithium-ion storage capacity

Cobalt monoxide (CoO) has received considerable attention because of promising applications in lithium-ion batteries (LIBs). However, nanostructured CoO anode materials still suffer from the poor conductivity and large volume change. By optimizing the morphology and introducing the proper dopants, some of the obstacles can be overcome. In this work, a fan-shape Mn-doped CoO/C microsphere (Mn-CoO/C) composite is synthesized by a one-step hydrothermal process and the electrochemical properties are evaluated systematically. The Mn-CoO composite has a flabellum structure with a length of 5–10 µm assembled on nanosheets with a size of 20–50 nm. The interlayer spacing is 30–100 nm and the Co to Mn ratio is 8:1. The Mn-CoO/C electrode shows a high specific capacity of 741.2 mAhg⁻¹ at 0.1 C as well as good cycling stability. To demonstrate the practicality of the electrode materials, the lithium-ion battery shows a capacity of 726.4 mAhg⁻¹ after 200 cycles. The large specific surface area and short ion/electron transfer paths lead to the excellent electrochemical performance and our results reveal a simple and practical strategy to improve the lithium storage capacity of LIBs.