标题：Porosity- and Graphitization-Controlled Fabrication of Nanoporous Silicon@Carbon for Lithium Storage and Its Conjugation with MXene for Lithium-Metal Anode
作者：An, Yongling; Tian, Yuan; Wei, Hao; Xi, Baojuan; Xiong, Shenglin; Feng, Jinkui; Qian, Yitai
作者机构：[An, Yongling; Tian, Yuan; Wei, Hao; Feng, Jinkui] Shandong Univ, Sch Mat Sci & Engn, SDU & Rice Joint Ctr Carbon Nanomat, Key Lab Liquid Solid Struct 更多
通讯作者地址：[Feng, JK]Shandong Univ, Sch Mat Sci & Engn, SDU & Rice Joint Ctr Carbon Nanomat, Key Lab Liquid Solid Struct Evolut & Proc Mat,Min, Jinan 250061, Sha 更多
来源：ADVANCED FUNCTIONAL MATERIALS
关键词：controlled fabrication; lithium-ion batteries; lithium-metal batteries;; MXene; silicon@carbon anodes
摘要：Silicon (Si) and lithium metal are the most favorable anodes for high-energy-density lithium-based batteries. However, large volume expansion and low electrical conductivity restrict commercialization of Si anodes, while dendrite formation prohibits the applications of lithium-metal anodes. Here, uniform nanoporous Si@carbon (NPSi@C) from commercial alloy and CO2 is fabricated and tested as a stable anode for lithium-ion batteries (LIBs). The porosity of Si as well as graphitization degree and thickness of the carbon layer can be controlled by adjusting reaction conditions. The rationally designed porosity and carbon layer of NPSi@C can improve electronic conductivity and buffer volume change of Si without destroying the carbon layer or disrupting the solid electrolyte interface layer. The optimized NPSi@C anode shows a stable cyclability with 0.00685% capacity decay per cycle at 5 A g(-1) over 2000 cycles for LIBs. The energy storage mechanism is explored by quantitative kinetics analysis and proven to be a capacitance-battery dual model. Moreover, a novel 2D/3D structure is designed by combining MXene and NPSi@C. As lithiophilic nucleation seeds, NPSi@C can induce uniform Li deposition with buffered volume expansion, which is proven by exploring Li-metal deposition morphology on Cu foil and MXene@NPSi@C. The practical potential application of NPSi@C and MXene@NPSi@C is evaluated by full cell tests with a Li(Ni0.8Co0.1Mn0.1)O-2 cathode.