Ordered nanorods assembled MnCO3@reduced graphene oxide anodes for high-performance lithium-ion capacitors: A facile thiourea-assisted reduction approach

Abstract

MnCO3 materials owing to considerable capacity, good stability and low price, show a great potential in lithium-ion capacitors (LICs) applications. The design and synthesis of MnCO3 with ordered and fine structure regulation are currently challenging issues. A facile thiourea-assisted reduction strategy is established for preparing ordered nanorods assembled MnCO3 wrapped by reduced graphene oxide (MnCO3@rGO). This composite exhibits a multi-channel charge transfer model within the oriented structure and high connectivity of conductive graphene oxide network. Based on the unique structure, the MnCO3@rGO anode shows a high capacity of 1885 mA h g−1 at 0.2 A g−1, vibrant rate performance (383 mA h g−1 at 10 A g−1) as well as sturdy cycle. Moreover, the assembled LICs with the MnCO3@rGO displays an excellent energy density of 204 W h kg−1, high power density of 30 kW kg−1, and robust capacity retention of 78% after 10000 cycles. Additionally, the corresponding flexible device holds a stable energy supply under different bending conditions. This work provides a promising approach for the preparation of high-performance metal carbonates-based materials with fine micro/nano structure.