Na-Mn-O@C yolk-shell nanorods as an ultrahigh electrochemical performance anode for lithium ion batteriesElectronic supplementary information (ESI) available. See DOI: 10.1039/c7ta06046g

A considerable amount of intensive research has been made towards efficient energy storage, particularly regarding rechargeable lithium-ion batteries (LIBs). However, there are still huge limitations to the applications of state-of-the-art LIBs, including their inadequate durability, safety concerns and high costs, and so they cannot meet the ever-growing demand for portable electronic devices and power batteries. Therefore, designing viable LIBs with high cost efficiency and performance through integration of new alternative electrode materials possessing well-controlled nanostructures is critical. Herein, we rationally design a facile and effective method to construct Na 0.55 Mn 2 O 4 ·1.5H 2 O@C (SMOH@C) yolk-shell nanorods which integrate a one side internal void with the outer carbon shell framework. By virtue of such a yolk-shell structure and composition, as an anode material, the as-built electrode endows LIBs with attractive electrochemical performances including a high specific reversible capacity (750 mA h g −1 at 0.1 A g −1 ), an excellent rate and superior long term cycling capability (448 mA h g −1 capacity retention after 3000 cycles at 4.0 A g −1 ). This unique structure design strategy paves the way to produce new anode materials with superior performances for next-generation LIBs. By virtue of its unique yolk-shell structure and composition, the as-built Na 0.55 Mn 2 O 4 ·1.5H 2 O@C electrode endows LIBs with attractive electrochemical performances.