Preparation And Electrochemical Energy Storage Of Carbon Matrix Composites

Nowadays,technologies such as artificial intelligence and the Internet of Things are in full swing and green and environmentally friendly electric vehicles are vigorous popularization.The development of society and the actual needs of people have put forward higher requirements for the comprehensive performance of power sources.At present,due to the limit of electrode materials and lithium reserves on the commercial lithium-ion batteries?LIBs?,it cannot meet the demand for batteries with high energy density,power density and low-cost.It is urgent to explore high performance anode materials that can replace graphite.Potassium ion batteries?KIBs?have attracted widespread attention due to their similar reaction mechanisms and process systems as LIBs,with lower electrode potentials,and abundant potassium reserves.However,due to the large radius of potassium ions,it is easy to cause damage to the electrode structure and cause capacity degradation.Therefore,exploring a novel anode material will greatly benefit the development of LIBs/KIBs.The carbon-based composite materials are selected as the anode materials for the LIBs/KIBs.On the one hand,it exerts the good conductivity and structural stability of the carbonaceous material,and on the other hand,alloyed materials?tin and antimony?and conversion materials?ferric iron oxide?with high theoretical capacity are combined.What's more,by designing a reasonable structure and the generation of nanoparticles,anode materials with good electrochemical performance are prepared.In this article,we use carbon matrix-coated metal tin?Sn@C?,carbon-coated ferric oxide?Fe₃O₄@C?,and carbon fiber-coated metal antimony?Sb@C?as LIBs/KIBs anode materials and study various characteristics including electrochemical performance,providing a variety of ideas for the development of alkaline metal batteries.The specific summaries are as follows:?1?Sodium polyacrylate is used as a carbon source,swell after absorbing tin tetrachloride solution,and generate in-situ NaCl template after freeze-drying.After carbonization,a three-dimensional framework structure coated with tin nanoparticles composite material is studied as an anode material for LIBs.It has a large specific surface area?221.1 m²/g?and shows good circulation capacity(1036 mA g h^-1 after 60cycles at 50 mA g^-1).Moreover,the method of prelithiation is applied for increasing the initial Coulomb Efficiency of the material from 72.4%to 91.2%.?2?The application of conversion anode materials ferric oxide?Fe₃O₄?in lithium/potassium ion batteries are investigated.A simple high-temperature solid-phase method is used to construct a porous carbon matrix,in which ferric oxide particles are uniformly dispersed.When used as anode materials for KIBs,the Fe₃O₄@C at 700?performs the best comprehensive electrochemical properties by compared the different carbonization temperatures,which exhabits high capacity retention rate?87.7%?and the reversible capacity(285 mA h g^-1).The Fe₃O₄@C at 700?is explored the electrochemical performance as the anode of LIBs.After 50 cycles at 50mA g^-1,the capacity is 837 mA h g^-1,with a retention rate of 89.8%.The cyclic voltammetry method is conducted to verify the proportion of capacitive behavior contribution in potassium storage.?3?One-dimensional carbon-coated antimony nanofibers are prepared by electrostatic spinning technology.As an anode material for KIBs,it exhibits high cycle capacity with 369 mA h g^-11 at 50 mA g^-1 after 50 cycles and excellent rate performance with a capacity of 172.9 mA h g^-1 at 2 A g^-1,and the capacity retaining417.1 mA h g^-1 when the current returns to 0.05 A g^-1.In this paper,there are 30 figures,2 tables and 126 reference articles.