Study On Preparation Of Porous Manganese Based Materials Via A Self-templating Method And Its Electrochemical Energy Storage

It is well known that the lack of non-renewable resources for human beings, increasing the use of renewable resources has become inevitable. Meanwhile, the demand for electronic products in people’s daily life is also increasing. This makes energy storage technology become the key to the future development of energy systems. The most popular is electrochemical energy storage technology, which is dominated by lithium-ion battery and supercapacitor, and has highly industrialization prospect. Electrode material is the core of electrochemical energy storage technology, which directly determines the performance of energy storage devices. Therefore, the researchers consume a lot of time to update the composition and structure of the material, hoping to produce the best performance material. Because of its low density, large surface area, stability and surface permeability, porous materials have become a hot topic. Herein,using cubic PB analogues as precursor, the different components and structures of manganese based porous materials were prepared via a self-templating method, and the electrochemical performance of materials was studied. Specific research results are as follows:1.3D mesh Mn₇O₁₃·5H₂O material was synthesized via a self-templating method using cubic Mn₃[Fe（CN）₆]₂ as precursor. Research results show that under our experimental conditions, the product can successfully maintain the cubic structure by replacing the [Fe（CN）6]3-. The 3D mesh Mn₇O₁₃·5H₂O revealed a specific capacitance of 248 F g-1 at 5 mV s-1 and a good cycling stability with capacitance retention of 73% after 1000 cycles. Hollow porous Mn3O4 material was prepared by calcinating the Mn₇O₁₃·5H₂O under 500℃. At a scan rate of 5 mV s-1, the hollow porous Mn3O4 exhibited specific capacitance of 354 F g-1 and showed excellent cycling stability with capacitance retention of 77% after 8000 cycles. The Mn₇O₁₃·5H₂O obtained here can seldom be studied as electrode material and the electrochemical properties of Mn3O4 material is higher than that reported in literature.2. Porous MnSn（OH）6/SnO2 composite was synthesized via a self-templating method by changing the contents of sodium stannate, reaction time et al. Reseach results suggest that the composite well keeped the cubic structure of the precursor. The porous MnSn（OH）6/SnO2 exhibited enhanced performance as electrode for pseudocapacitors and revealed a specific capacitance of 341 F g-1 at 1 mV s-1. The porous MnSn（OH）6/SnO2 also achieved 72% capacitance retention after 1000 cycles. The synergistic effect of MnSn（OH）6 and SnO2 may make the composite exhibit excellent performance.3. Porous hollow Mn₃（PO₄）₂·3H₂O material was obtained via a self-templating method by adjusting phosphorus sources, phosphorus content and reaction time et al. The porous hollow Mn₃（PO₄）₂·3H₂O well retained the cubic shape of the Mn₃[Fe（CN）₆]₂ precursor. In addition, the porous hollow Mn₃（PO₄）₂·3H₂O exhibited a specific capacitance of 324 F g-1 at 1 mV s-1 as a electrode for pseudocapacitors and 98% capacitance retention was achieved after 5000 galvanostatic charge-discharge cycles. So the porous hollow Mn₃（PO₄）₂·3H₂O is very promising for high-performance supercapacitors.