Novel stacked nanosheets of Mn 3 O 4 thin films were synthesized on a large scale by a facile and efficient low-temperature chemical bath deposition (CBD) route, without templates or surfactants. The aligned nanosheets have a high surface area and a mesoporous structure, which were expected to help to improve the electrochemical property in Li + batteries. This synthetic procedure is straightforward, inexpensive and thus facilitates mass production of Mn 3 O 4 stacked nanosheets. The automobile market is presently aimed toward the development of low emission cars, such as hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs), and of zero emission, full electric vehicles (EVs). 1 Making these sustainable vehicles a reality still depends on the availability of suitable energy storage systems such as high energy lithium ion batteries. Great efforts have been devoted to develop different types of materials with high reversible capacity, long cycle life, and low cost. 2 Electrochemically active metal oxides such as SnO 2 , Fe 2 O 3 , Co 3 O 4 , MnO 2 and NiO have long been considered as promising anode materials for lithium ion batteries because of their higher theoretical capacities and high energy densities than those of conventional graphite anodes (372 mAh g 21). 3 However, these materials suffer from poor stability due to the pulverization process, although efforts have been taken to improve the cyclability and specific capacity through nanostructuring transition metal oxides. 4 Among different nanostructured transition metal oxides, manga-nese oxides are some of the most attractive materials for battery electrode due to their low cost, great environmental compatibility and good specific capacity. 5 There are different polymorphs of manganese oxide (MnO, Mn 3 O 4 , MnO 2), among them Mn 3 O 4 undergoes relatively little research. However, it plays important roles in energy storage, catalysts, soft magnetic materials etc., and has recently drawn growing attention. 6 As far as we know, only a few reports were related to the Li-ion battery properties of Mn 3 O 4 material. Surprisingly, previous reports of Mn 3 O 4 have suggested that the material has poor lithiation activity, despite being isostructural with Co 3 O 4 . In one report, pure Mn 3 O 4 was shown to have a reversible capacity of just 200 mAh g 21 , whereas a cobalt-doped sample of Mn 3 O 4 exhibited a stable reversible capacity of 400 mAh g 21 with a first coulomb efficiency of 45%. 7 The activity of electrode materials is primarily determined by the microstructure of active species. Various nanostructures of Mn 3 O 4 such as nanorods/ nanowires, mesoporous/hollow spheres, nanofibers have been synthesized by different routes, such as solid state reaction, chemical bath deposition and c-ray irradiation. 8 Especially, CBD method as a typical solution-based approach has been proven to be an effective and convenient process in preparing various inorganic materials with diverse controllable morphologies and architectures directly on the substrates. 9 Herein, a mild, simple and scalable strategy has been developed to realize the synthesis of self-assembly of stacked layers of Mn 3 O 4 nanosheets (2D). The size and crystalline nature of the stacked nanosheets layers can be tuned easily by changing the concentration of complexing agent. The results indicate that this type of Mn 3 O 4 exhibits a high initial capacity of 824 mAh g 21 . The Li storage performance of Mn 3 O 4 electrodes was much better than those reported for manganese oxide based anode materials. High surface area and a mesoporous structure of well-arranged stacked nanosheets help to improve the electrochemical property in Li + batteries. Although the specific capacity reported here is lower than the previously reported values for Mn 3 O 4 , this material can be used as new and promising electrode material in battery application due to better stability and high rate capability. Synthesis of stacked nanosheets of Mn 3 O 4 thin films by CBD method is based on immersing the titanium substrates into an aqueous solution of manganese sulfate complexed with hexamethy-lenetetramine (HMT). Firstly, solutions of 0.1 M manganese sulfate as a source of manganese with two different concentrations of HMT (0.05 and 0.1 M) were prepared. Well cleaned titanium substrates were immersed in these above prepared two baths placed at temperature of 343 K. When the bath attained the temperature of 343 K, the brownish precipitation started in the bath. During precipitation, a heterogeneous reaction occurred and Mn 3 O 4 was deposited on the substrates. The deposition time for Mn 3 O 4 sample placed at 343 K is kept constant at 3 h for both baths. The films were annealed at 473 K for 2 h, in order to remove hydroxide and to improve the crystallinity of deposited films. The films obtained after the deposition period of 3 h for the HMT concentration of 0.05 and 0.1 M are hereafter symbolized as M1 and M2, respectively. For experimental set up see ESI, Fig. S1.{