Application Of Antimony-based Composite Materials In Sodium Ion Batteries

Antimony?Sb?is regarded as an attractive anode material for sodium-ion batteries?SIBs?due to its high theoretical capacity of 660 mAh g^-1.But Sb was found to have severe volume expansion when applied in sodium ion batteries.Combining Sb with carbonaceous materials has been considered an effective way to resolve the serious volume expansion issues.Sb/C composites mainly consist of two types,that is,Sb confined inside a carbon matrix and Sb deposited on the surface of a carbon matrix,and both have shown superior sodium storage performance.However,which structure is more beneficial for achieving high electrochemical performance is still unclear.In this work,We proposed a scheme,using the same synthesis method,to obtain two Sb/C composite materials with different structures through different treatments.The morphology and composition of the carbon matrix and the particle size of Sb of the two materials are the same,but the positions of Sb are different.The electrochemical analysis of the two materials with different structures is compared.The main research contents are as follows:?1?First,Cu NWs with uniform thickness are synthesized by hydrothermal method,and then the Cu NWs are coated with a C shell by hydrothermal method and high temperature sintering.The thickness and thickness of the C shell are uniform,and they can completely cover the Cu NWs.Cu was confined in C NTs to form a Cu@C structure.The Cu@C structure can prevent Cu NWs from contacting the outside air,and at the same time,it can delay their oxidation and react with other substances.?2?Then,Cu@C was put into the SbCl₃-DMSO reaction system through different treatment methods,and two kinds of Sb/C composite materials with different structures meeting the above problems were synthesized by the nano-constrained current displacement reaction.They are peapod-like Sb@C NTs with Sb particles confined inside the C NTs,and corn-like C@Sb NTs with Sb particles attached to the outer walls of the C NTs.These two materials were used as model materials for sodium storage to explore the above issues.?3?Electrochemical analysis of peapod-like Sb@C NTs and corn-like C@Sb NTs.When evaluated as anode materials for SIBs,the peapod-like Sb@C shows a higher rate capability and a significantly better long-term cycling stability than those of the corn-like C@Sb.Electrochemical analysis reveals that the peapod-like Sb@C exhibits faster Na⁺and electron transport kinetics and higher proportions of surface capacitive contributions.These results demonstrate the structural superiority of the nanoconfined structure and provide valuable information for the rational design and construction of Sb-based anode materials for high-performance electrochemical energy storage.