A Low‐Surface‐Tension Strategy to Construct Ultrathin Reduced Graphene Oxide as Lithiophilic Matrix for Lithium Metal Anode

Abstract

Lithium metal is regarded as “holy grail” in the secondary rechargeable batteries. However, irregular Li deposition and dead lithium during the plating/striping process lead to serious safety issues and rapid capacity decay. The low conductivity of matrix and inhomogeneous ion transfer result in the growth of lithium dendrite and thus the low coulombic efficiency. Here, the authors propose to solve this issue by constructing highly conductive matrix with regulated charge transfer. A low surface tension (LST) strategy is adopted to construct ultrathin reduced graphene oxide (UrGO) to storage Li. The ultrathin and loose structure promise UrGO with high conductivity and the uniformly distributed residue oxygen‐containing groups helps to induce the uniform deposition of lithium due to the improved affinity to Li. The obtained UrGO with high conductivity shows a low lithium nucleation overpotential. The UrGO@Li electrode reveals an outstanding electrochemical stability with a high coulombic efficiency of 98.5% for over 300 cycles. The good performances of full cell also indicate the successful design of the UrGO matrix and the LST strategy provides a new vision for designing highly conductive graphene‐based porous materials.

Magnesium Anchoring Strategy for Stabilizing Graphene‐Hosted Lithium Metal Battery

“…[ 19 ] Among those strategies, the lithiophilic reduced graphene oxide (rGO)‐based host materials offer unique advantages of fabricating microlevel ultrathin and mechanical robust Li metal–rGO composite foil for both prelithiation and energy‐dense Li metal battery applications. [ 20–25 ] However, the oxygen‐containing function groups (including hydroxyl –OH, carboxyl –COOH, and epoxyl C–O–C groups) in the rGO host are very likely to be electrochemically reduced with chemical bond ruptured in anode, generating less‐stable lithium carbonate species (Li 2 CO 3 and lithium ethylene decarbonate, LEDC) in SEI that contribute to Li dendrite growth and cycling irreversibility. [ 26 ] To date, the mechanism and resolution of host decomposition‐involved SEI composition variations have rarely been proposed or addressed.…”

“…[19] Among those strategies, the lithiophilic reduced graphene oxide (rGO)-based host materials offer unique advantages of fabricating microlevel ultrathin and mechanical robust Li metal-rGO composite foil for both prelithiation and energy-dense Li metal battery applications. [20][21][22][23][24][25] However, the oxygen-containing function groups (including hydroxyl -OH, carboxyl -COOH, and epoxyl C-O-C groups) in the rGO host are very likely to be electrochemically reduced with chemical bond ruptured in anode, generating Lithium metal-graphene host composite is a promising anode material for high-energy-density Li battery owing to its three-dimensional structure, microlevel controllable thickness and ultrahigh specific capacity. However, we discover that the hydroxyl/carboxyl functional groups in the reduced graphene oxide (rGO) host are likely to be reduced into lithium carbonate composition in the solid-electrolyte interphase (SEI), which resulted in severe lithium dendrite growth that deteriorate its electrochemical performances.…”

The Preparation of Carbon Nanotubes/Reduced Graphene Oxide Current Collector by Non-covalent Induction of Ionic Liquid for Sodium Metal Anode

“…离子液体(IL)是一种仅由阴阳离子 组成的室温融盐. 咪唑基离子液体与 sp 2 碳之间存在较 强的静电/π-π 相互作用, 可以有效地稳定 sp 2 碳材料, 防 止 sp 2 型碳材料的堆叠/团聚 [33][34] .…”