Sustainable silicon anodes facilitated via a double-layer interface engineering: Inner SiOx combined with outer nitrogen and boron co-doped carbon  

作　　者：Jun Zhou Yao Lu Lishan Yang Wenqiang Zhu Weifang Liu Yahui Yang Kaiyu Liu 

机构地区：[1]Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research(Ministry of Education),National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of Resources,Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province,Hunan Normal University,Changsha,Hunan,P.R.China [2]College of Chemistry and Chemical Engineering,Central South University,Changsha,Hunan,P.R.China

出　　处：《Carbon Energy》2022年第3期399-410,共12页碳能源（英文）

基　　金：supported by Joint Funds of the National Natural Science Foundation of China(U20A20280);the National Natural Science Foundation of China(21805083,52074119);the Academy of Sciences large apparatus United Fund of China(U1832187);the Scientific Research Fund of Hunan Provincial Education Department(19K058);the Science and Technology Planning Project of Hunan Province(2018TP1017);the High-Tech Leading Plan of Hunan Province(2020GK2072).

摘　　要：Silicon-based(Si)materials are promising anodes for lithium-ion batteries(LIBs)because of their ultrahigh theoretical capacity of 4200 mA h g^(−1).However,commercial applications of Si anodes have been hindered by their drastic volume variation(∼300%)and low electrical conductivity.Here,to tackle the drawbacks,a hierarchical Si anode with double-layer coatings of a SiOx inner layer and a nitrogen(N),boron(B)co-doped carbon(C-NB)outer layer is elaborately designed by copyrolysis of Si-OH structures and a H3BO_(3)-doped polyaniline polymer on the Si surface.Compared with the pristine Si anodes(7mA h g^(−1) at 0.5 A g^(−1) after 340 cycles and 340 mA h g^(−1) at 5 A g^(−1)),the modified Si-based materials(Si@SiOx@C-NB nanospheres)present su perior cycling stability(reversible 1301 mA h g^(−1) at 0.5 A g^(−1) after 340 cycles)as well as excellent rate capability(690mA h g^(−1) at 5 A g^(−1))when used as anodes in LIBs.The unique double-layer coating structure,in which the inner amorphous SiOx layer acts as a buffer matrix and the outer defect-rich carbon enhances the electron diffusion of the whole anode,makes it possible to de liver excellent electrochemical properties.These results indicate that our double-layer coating strategy is a promising approach not only for the devel opment of sustainable Si anodes but also for the design of multielement-doped carbon nanomaterials.

关 键 词：boron-nitrogen co-doped carbon coating silicon anode stability WETTABILITY 

分 类 号：TQ127[化学工程—无机化工]