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Ultrathin Bilayer of Graphite/SiO 2 as Solid Interface for Reviving Li Metal Anode
Author(s) -
Pathak Rajesh,
Chen Ke,
Gurung Ashim,
Reza Khan Mamun,
Bahrami Behzad,
Wu Fan,
Chaudhary Ashraf,
Ghimire Nabin,
Zhou Bin,
Zhang WenHua,
Zhou Yue,
Qiao Qiquan
Publication year - 2019
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201901486
Subject(s) - materials science , anode , electrolyte , bilayer , graphite , chemical engineering , lithium (medication) , plating (geology) , cathode , electrode , composite material , membrane , chemistry , biology , engineering , genetics , medicine , geophysics , geology , endocrinology
Lithium metal anodes are expected to drive practical applications that require high energy‐density storage. However, the direct use of metallic lithium causes safety concerns, low rate capabilities, and poor cycling performance due to unstable solid electrolyte interphase (SEI) and undesired lithium dendrite growth. To address these issues, a radio frequency sputtered graphite‐SiO 2 ultrathin bilayer on a Li metal chips is demonstrated, for the first time, as an effective SEI layer. This leads to a dendrite free uniform Li deposition to achieve a stable voltage profile and outstanding long hours plating/stripping compared to the bare Li. Compared to a bare Li anode, the graphite‐SiO 2 bilayer modified Li anode coupled with lithium nickel cobalt manganese oxide cathode (NMC111) and lithium titanate shows improved capacity retention, higher capacity at higher rates, longer cycling stability, and lower voltage hysteresis. Graphite acts as an electrical bridge between the plated Li and Li electrode, which lowers the impedance and buffers the volume expansion during Li plating/stripping. Adding an ultrathin SiO 2 layer facilitates Li‐ion diffusion and lithiation/delithiation, provides higher electrolyte affinity, higher chemical stability, and higher Young's modulus to suppress the Li dendrite growth.