Electrochemical performance was evaluated using button coin

It is well-known that (-)-JQ1 commercial graphite anode suffers from low theoretical specific capacity (372 mAh g−1) and poor rate capability [5]. To solve these problems, substantial efforts have been made to develop new anode materials for the next-generation LIBs, such as the metal oxide nanomaterials (including SnOx, MnOx, FeOx, NiOx, CoOx, CuO, etc.) [6], [7], [8], [9], [10], [11], [12] and [13]. Among these alternatives, MnOx (MnO2, Mn4O3, Mn2O3, MnO) has received particular interest because of its high specific capacity, low environmental footprints both in synthesis and applications, abundant resources, and low cost [14]. However, there are several hurdles when using MnOx as anode materials: (i) low electronic conductivity (10−6-10−8 S cm−1) and (ii) large volume change (>170%) during the lithiation/delithiation processes, which result in poor rate capability and fast capacity decay [15]. To circumvent these critical issues, there are two effective strategies: (i) reducing MnOx particle size down to nanoscale range because the nanostructures can shorten the electronic/ionic distance for improved electrode reaction kinetics; (ii) compositing MnOx with carbon materials because carbon can act as a buffering barrier to accommodate the volume change of MnOx and can increase the electrical conductivity to enhance the electron transfer rate. By combining the two strategies, various kinds of MnOx/carbon (e.g., carbon coating, carbon nanotube (CNT), graphene, carbon nanofiber (CNF), mesoporous carbon) nanocomposites have been developed and showed improved capacity and cycling performance [7], [8], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24] and [25]. It is noted that most of these studies are related to powder-like nanomaterials, which require extra binders, conductive agents and current collector to constitute an electrode. In addition, the conventional slurry-casting procedure during the electrode fabrication is complex and time-consuming.