| Serious pollution of environment and the excessive consumption of fossil fuels have become the key factors to restrict the development of the society,so the research and development of new energy technology is an effective way to solve the above problem,which have become the focus of the industry-university-research subject.With an eye to improve the performance of Li-ion battery,supercapacitor and water splitting,research and development of new electrode with high conversion efficiency for electric energy and chemical energy is the key to the new energy materials.During this process,the electrochemical method will play a very important role in energy storage and conversion being used in Li-ion battery,supercapaciory and water splitting.Based on the defferent demand for different energy storage,the research and development of electrode materials is the key to the high-performance energy storage devices.Mesporous/Hollow micro/nano-structures with high surface area,large nanoscale interiors,and good mass permeability have been widely used in electrochemical energy storage and conversion.But it is still a key problem to further improve its application possibility about how to design and synthesize electrode materials with mesoporous/hollow structure.In this paper,the main research content is that designing and synthesis of electrode materials with mesoporous/hollow structure being used in Li-ion battery,supercapatior and electrochemical water splitting based on the self-sacrificed template method to improve their electrochemical energy storage and catalytic properties,which will enhance their application in the field of energy storage and conversion and provide help for its application in energy storage devices.The main research contents and results as follows:1?We propose the concept of predefined internal porosity through the morphologic engineering of active materials for high-performance lithium storage.This bottom-up approachallows the control of porosity of individual particles of activematerials.The electrode porosity is thus predefined by the porosity and structure of the active material,instead of poreformation through conventional methods which are definedby the slurry coating process of the electrode after prepara-tion treatments.In this article,uniform CaTiO3 microcubes were synthesized as self-sacrificial templates for TiO2 using a facile solvothermal method,then a straightforward,effective route for the synthesis of hollow TiO2 microboxes through a Na2EDTA-assisted ion exchange.The synthesis of TiO2 microboxes further confirm that the concept of predefined internal porosity of active material.2.We introduce a new strategy to fabricate a nitrogen-doped C/Ni/TiO2 composite with a unique hollow spindle structure.The synthesis involves a facile precipitation process and a subsequent high temperature reduction treatment under inert atmosphere.The novel structure can provide a large active surface area for high efficiency electrochemical reaction and greater Li-ion packing density,as well as a short diffusion length for lithium ion transport.3.We report an effective route for synthesis of ternary Ni-Co sulfide hollow structures with tunable compositions as electrode materials for high-performance ECPCs.At the beginning,Cu2O nanocubes are fabricated as the template.With Na2S2O3 solution continuously dropping,Cu2O nanocubes are gradually removed by forming a soluble complex,and then OH-ions are released.At the same time,Ni2+and Co2+ species coprecipitate with OH-ions to form Ni-Co hollow precursors with mesoporous shells.After a sulfidation process with thiourea as sulfur source,we first developed mesoporous NiCo2S4 nanoboxes with a well-defined hollow interior,which were applied as electrode materials for ECPCs.4.We report hierarchical NiCo2O4 hollow microcuboids,constructed by 1D nanowires,as bifunctional electrocatalysts for both the HER and OER as well as overall water splitting.These novel hierarchical NiCo2O4 hollow microcuboids show excellent catalytic activity and stability towards overall water splitting.For example,the current density of 10 mA cm-2 current was reached by applying just 1.65 V,while the current density of 20 mA cm-2 was obtained by applying just 1.74 V across the two electrodes.The synthesis of NiCo2O4 microflowers for comparison further confirms the importance of structural features for high-performance water splitting.All of these results make hierarchical NiCo2O4 hollow microcuboids excellent electrode materials for practical applications in overall water splitting. |
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