Preparation Of Porous Materials And Their Research On Lithium Sulfur Batteries And Carbon Dioxide Capture

With the development of human society,the massive burning of non-renewable fossil fuel has caused serious environmental and energy depletion problems.Therefore,in order to solve the above two problems,we need to develop renewable clean energy and develop corresponding energy storage facilities.However,based on the current social development,fossil fuels will continue to be our indispensable energy source.Therefore,it is very important to develop corresponding energy storage equipment and to develop efficient CO₂ capture technology at the same time.As a portable energy storage device,batteries are widely used in our lives.However,the widely used lithium-ion batteries at this stage cannot withstand the demand for high-capacity energy storage devices such as electric vehicles due to the limited theoretical specific capacity of the cathode material.Lithium-sulfur batteries with high theoretical specific capacity,theoretical specific energy,and a wide range of sources of active material sulfur,non-toxic and harmless.In addition,based on the current development needs of human society,fossil fuel will continue to be an indispensable energy source in the development of our society,Due to the large specific surface area of MOFs,functional functional groups have been widely studied in terms of CO₂ capture.However,the synthesis of MOFs is usually time-consuming and energy-consuming,so efficient synthesis a MOFs with high CO₂ adsorption capacity for CO₂ is very important.This article focuses on these two aspects:On the one hand,although lithium-sulfur batteries have outstanding commercial prospects,there are still some key issues to be solved.How to effectively suppress the shuttle effect of polysulfides has become a current research hotspot.On the other hand,metal organic framework materials?MOFs?are considered to be very promising CO₂ adsorbents due to their many advantages such as large specific surface area,versatile organic ligands,and excellent CO₂ adsorption performance,but the hydrothermal synthesis method usually needs a lot of time and energy,which is block for large-scale synthesis.Therefore,it is very important to explore a suitable synthesis method to efficiently synthesize a highly adsorbed CO₂ adsorbent.The main research contents of this article are as follows:1.We synthesized silica nanospheres with porous hollow metal nickel and widely distribute through hydrothermal method,and combined with graphene to modify the commercial membrane to prepare a multifunctional separator,which effectively inhibit lithium polysulfide shuttling and improves the cycling performance of lithium-sulfur batteries.Through experimental research and theoretical calculations confirmed the functional mechanism of the functional separator.The battery modified with the functional separator show excellent electrochemical performance.Including superior cyclic stability(922 m Ah g^-1 after 100 cycles at 0.2 C,772 m Ah g^-1 after 300 cycles at 1 C).The Ni/Si O₂/Graphene-modified separator is able to anchor Li PSs through affinity towards Li PSs by silica and Ni atoms,and enable rapid conversion between Li PSs and Li₂S₂/Li₂S by abundant Ni catalytic sites.The mesoporous hollow structure of the Ni/Si O₂ nanosheet spheres also facilitates Li⁺diffusion.2.The synthesis method by microwave radiation not only shortened the preparationtime greatly,but also successfully prepared a MOFs with high CO₂ adsorption capacity.Because the organic ligands constituting MOFs contain a large amount of N atoms,carbon dioxide is captured by the strong interaction of carbon and nitrogen atoms.The MOFs exhibit high CO₂ adsorption capacity(89 mg g^-1,298 K,1 bar and 53 mg g^-1,298 K,0.15bar)and high adsorption selectivity,reversible CO₂ adsorption-desorption cycle,and excellent Moisture stability.