Research On Sodium Ions Storage Property Of Three Biomass Carbon With Various Microstructure Composed With Antimony Sulfide

With increasing demand for new energy storage equipment,the commercial lithium-ion batteries have no longer been qualified to apply in large-scale energy storage due to its high cost and limited resources.Meanwhile,sodium resources,which were found by researchers,are very rich and distributed all over the world.Therefore,sodium ion batteries have attracted people's attention due to low cost,environment-friendly and compatible with the available lithium-ion batteries production equipment.Moreover,s odium batteries not only have favourable safety performance,but also can work normally under a wide temperature range.Nevertheless,sodium batteries cannot achieve its whole potential because of its larger ionic radius.Hence,it is a hot research to find a new type anode materials which access favourable electrochemical and economy and environmental protection.In.this paper,we used three biomass raw materials to prepare hard carbon and apply them to the sodium anode electrode.Then we study different micro-structure hard carbon materials impact on sodium battery electrochemiacal performance and in-situ grow Sb2S3 on the different micro-structure biomass carbon materials to prepare biomass and metal sulfide compound materials of sodium battery anode electrode.Sulfide can enhance the storage sodium property by using its alloy-conversion reaction while biomass hard carbon materials can act as a buffer matrix and provide the electronic conductive path.Finally,the high capacity sodium batteries were obtained.The specific work is as follows:(1)The three types wasted biomass were selected as the raw materials which own different micro-structure,the one dimension structure of catkin,two dimension structure of sakura petal and three dimension structure of sucrose microsphere were included.We prepared three hard carbon materials which derived from different dimensions micro-structure.The one dimension catkin hard carbon microtube obtained the highest capacity and its specific capacity reached 124 mAh g-1 at a current density of 20mA g-1 and a favourable rate performance obtained as well.The two dimension sakura carbon sheet obtained the most stable cycling performance which capacity retention reached 78%after 50 cycles.The three dimension sucrose carbon microsphere exhibite the highest initial coulombic efficiency at the value of 55%.(2)Three types of biomass carbon/Sb2S3 composite materials were obtained through in-situ grow Sb2S3 on the biomass carbon by the solvothermal method and the morphology are varies.The aggregation of Sb2S3 nano particles grown at the mouth and cracks of one dimension catkin hard carbon microtube;The low-crystallined Sb2S3 nano particles grown on the carbon sheet of the two dimension sakura petal and the rob-like Sb2S3 crystal were mixed as well.The three dimension sucrose carbon microsphere has no significant impact on the recrystallization of Sb2S3 and it just mixed at carbon sphere surface randomly.We apply the biomass carbon/Sb2S3 composite to the sodium battery anode electrode.The catkin carbon tube/Sb2S3 exhibite the best electrochemical performance of which the specific capacity reached at 178 mAh g-1 at the current density of 20 mA g-1.And its capacity remain at 95 mAh g-1 after 50 cycles and the coulombic efficiency is closed to 100%,the rate performance is the most stable as well.(3)Improving the Sb2S3 content of the three dimensions micro-structure biomass carbon to enhance the sodium storage performance of the composite materials by using its high specific capacity characteristic.The results show that catkin/Sb2S3-15 composite materials'electrochemical performance is the best which the specific capacity reached 227 mAh g-1 at current density of 20 mA g-1 and remain at 171 mAh g-1 after 50 cycles,the coulombic efficiency is closed to 100%.And the specific capacity reached at 95 mAh g-1 at the higher current density of 50 mA g-1 after 100 cycles.The outstanding electrochemical attribute to the one dimension structure catkin hard carbon could not only improve the electronic conductivity and physical limits the Sb2S3 to alleviate the volume expansion and but also shorten the ion diffusion path.Through study of the electrochemical reaction kinetics of the material,it can be seen that the reaction of the electrode is mainly controlled by the diffusion of sodium ions,which shows an obvious battery behavior.