【摘要】 锡基材料具有工作电压低、理论容量高等优点，是极具发展前景的锂离子电池负极材料。但其在循环充放电过程中，易发生严重的体积膨胀和结构坍塌，导致容量衰减严重，用多孔碳材料包覆后形成复合材料，是解决该缺陷的有效手段。本文以石油沥青为碳源和硫源，与Sn O₂混合后在高温下通过碳还原，制备了一种碳包覆的Sn/Sn S@C复合材料，采用XRD、SEM、TEM进行了表征，并测试了其电化学性能。沥青在高温下得到的碳为层状结构的非孔状材料，使用该碳材料包覆的Sn/Sn S@C复合材料，比容量约为沥青碳材料的2倍，在0.1A·g^-1电流密度下的首圈放电比容量为944.4 mAh·g^-1，之后随着充放电的进行，比容量逐渐降低，100圈循环后容量保持在527.6m Ah·g^-1，比容量保持率为55.9%。为保证复合材料的容量稳定性和充放电可逆性，SnO₂的掺杂量以10%左右为宜。更多还原

【Abstract】 Tin-based materials had the advantages of low operating voltage and high theoretical capacity,which was a promising anode material for lithium ion batteries.However,severe volume expansion occured during cycling,resulting in a rapid decreased in capacity.Coating with carbon materials was an effective means to overcome defects.In this paper,the carbon coated Sn/SnS@C composites were prepared via carbon reduction by mixing petroleum asphalt with SnO₂ at high temperature,in which the petroleum asphalt was used as carbon and sulfur sources.The synthesized composites were characterized by XRD,SEM,and TEM,and the electrochemical performance was tested.The carbon obtained from petroleum pitch at high temperature was lamellar non-porous material.The specific capacity of Sn/SnS@C composite coated by this carbon material was about twice that of the prepared carbon material,and the initial discharge capacity was 944.4mAh/g at the current density of 0.1A/g,then the specific capacity gradually decreased,and remained at 527.6 mAh/g over 100 cycles with a retention rate of 55.9%.To ensure the capacity stability and the charging/discharging reversibility,the doped amount of SnO₂ was about 10%.更多还原