| Porous carbon materials are considered to be the best candidates for the preparation of electrode materials with high electrochemical performance due to the characteristics of adjustable pore structure,easy to compound with other active substances.However,most porous carbon materials are powdered-form,limiting their application in flexible electronic devices.Besides,the preparation process of some other flexible porous carbon materials is relatively cumbersome.Therefore,it is meaningful research to develop a simple,efficient,well-developed,and easily modified flexible porous carbon materials construction technology.Membrane technology can build a developed porous structure and achieve flexibility through non-solvent induced phase separation(NIPS),which has been extensively explored in the field of separation.However,the research involved in the construction of high-performance carbon materials and application in the field of energy storage still needs to be carried out urgently.Therefore,this paper has carried out the following researches:Firstly,we proposed the concept of"electrode membrane".The 3D hierarchical nanoporous structure flexible electrode membranes were successfully prepared using polyacrylonitrile(PAN)as precursors and polyvinylpyrrolidone(PVP)and polyvinylidene fluoride(PVDF)as the pore-foaming agent through NIPS and carbonization technology.As supercapacitor electrodes,the maximum specific capacitance of the electrode membrane was 265 F g-1 in the three-electrode system and212 F g-1in the two-electrode system at a current density of 0.05 A g-1.After being assembled into an all-solid supercapacitor,it can still maintain 92%of the initial capacitance after 100 times of bending at 60o,and the capacitance retention rate was still as high as 81%after a long cycle of 2000 cycles.Secondly,3D hierarchical nanoporous structure controllable interpenetrating network electrode membranes were successfully prepared using PAN as precursors and PVP as the pore-foaming agent through NIPS and different carbonization temperatures.As anodes,the electrode membranes had a reversible capacity of 351.8 m A h g-1 and237.4 m A h g-1in lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)systems at a current density of 50 m A g-1,respectively.And all the electrode membranes exhibited stable cycling performance after cycling 200 times at 200 m A g-1.Thirdly,PAN/graphene/nano-silicon-carbon composite electrode membranes were constructed using PAN as the precursor,PVP as the pore-foaming agent,graphene as the flexible unit,and nano-silicon as the active material based on NIPS and carbonization technology.When used as LIBs anodes,the composite electrode membrane had a reversible capacity of 1135.7 m A h g-1.And the effective utilization rate of nano-silicon and composite electrode membranes was up to 92.6%and 92.9%,respectively,indicating that the volume effect of nano-silicon can be effectively alleviated after being composited with membrane technology.Fourthly,the Sn S2-CM composite electrode membranes were prepared using Sn Cl4·5H2O and thioacetamide as raw materials and the electrode membrane as the matrix by solvothermal technology.When used as the anode materials,the Sn S2-CM composite electrode membrane exhibits the reversible capacities of 839.8 m A h g-1 and573.7 m A h g-1 at 50 m A g-1 in LIBs and SIBs,respectively.Based on the destruction of the membrane porous structure,we clarified that the porous structure of the electrode membrane has a"constraining behavior"on alleviating the volume expansion of nano-active materials.Fifthly,the CM@Mo S2 composite electrode membranes were prepared using Na2Mo O4·2H2O and C3H7NO2S as raw materials and the electrode membrane as the matrix by hydrothermal technology.When used as the anode materials for SIBs,the reversible capacity of 472.2 m A h g-1can be obtained and the reversible capacity retention rate was up to 94.2%after 1000 cycles at 200 m A g-1.The CM@Mo S2//AC sodium ion capacitor was assembled with CM@Mo S2 composite electrode membrane as anode and the activated carbon AC as the cathode.Even at a high current density of2A g-1,the reversible capacity retention rate was still as high as 83.4%after 5000 cycles,and the average capacity attenuation in a per cycle is 0.00332%. |
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