摘要
硒化锡用于钠离子电池负极时具有较高的理论比容量且其成本低廉,因而备受关注.然而,由于其固有的低导电性,以及在充放电过程中的缓慢动力学和体积膨胀,硒化锡作为钠离子电池负极材料表现出的性能较差.本文首次合成SnSe2纳米晶耦合分层多孔碳微球(SnSe2NCs/C)用于增强钠离子电池的比容量、倍率能力和持久性.SnSe2NCs/C独特的结构可以有效阻止SnSe2纳米晶的团聚,减轻材料体积膨胀,加快电子和离子的扩散,增大电解液与电极材料的接触面积,提高材料结构的稳定性.所制备的SnSe2NCs/C微球具有较高的可逆比容量(在100 mA g^-1的电流密度下循环100圈后仍保持565 mA hg^-1的比容量),出色的倍率能力和长循环寿命稳定性(在1 Ag^-1的电流密度下循环1000圈后仍保持363 mAhg^-1的比容量).
Tin selenides have been attracting great attention as anode materials for the state-of-the-art rechargeable sodium-ion batteries(SIBs)due to their high theoretical capacity and low cost.However,they deliver unsatisfactory performance in practice,owing to their intrinsically low conductivity,sluggish kinetics and volume expansion during the charge-discharge process.Herein,we demonstrate the synthesis of SnSe2 nanocrystals coupled with hierarchical porous carbon(SnSe2 NCs/C)microspheres for boosting SIBs in terms of capacity,rate ability and durability.The unique structure of SnSe2 NCs/C possesses several advantages,including inhibiting the agglomeration of SnSe2 nanoparticles,relieving the volume expansion,accelerating the diffusion kinetics of electrons/ions,enhancing the contact area between the electrode and electrolyte and improving the structural stability of the composite.As a result,the as-obtained SnSe2 NCs/C microspheres show a high reversible capacity(565 mA h g^-1 after 100 cycles at 100 mA g^-1),excellent rate capability,and long cycling life stability(363 mA h g^-1 at1 A g^-1 after 1000 cycles),which represent the best performances among the reported SIBs based on SnSe2-based anode materials.
作者
陈辉
慕梓杰
李一举
夏仲宏
杨勇
吕帆
周金辉
晁玉广
王金淑
王宁
郭少军
Hui Chen;Zijie M u;Yiju Li;Zhonghong Xia;Yong Yang;Fan Lv;Jinhui Zhou;Yuguang Chao;Jinshu Wang;Ning Wang;Shaojun Guo(Department of Materials Science&Engineering,College of Engineering,Peking University,Beijing 100871,China;State Key Laboratory of Electronic Thin Film and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,China;State Key Laboratory of Marine Resource Utilization in South China Sea,Hainan University,Haikou 570228,China;BIC-ESAT,College of Engineering,Peking University,Beijing 100871,China;Department of Energy and Resources Engineering,College of Engineering,Peking University,Beijing 100871,China)
基金
supported by the National Key R&D Research Program of China (2016YFB0100201)
Beijing Natural Science Foundation (JQ18005)
the National Natural Science Foundation of China (51671003, 21802003)
China Postdoctoral Science Foundation (2019TQ0001)
the start-up supports from Peking University and Young Thousand Talented Program