Sodiophilic and conductive carbon cloth guides sodium dendrite-free Na metal electrodeposition

摘要

Sodium metal battery(SMB)technology is one of the most promising candidates for next-generation rechargeable energy storage systems due to its high theoretical capacity and economical costeffectiveness.Unfortunately,its practical implementation is hindered by several challenges including short life-span and fast capacity decay,which is closely related to the uncontrollable generation of the sodium dendrites.Herein,a nitrogen and oxygen co-doped three-dimensional carbon cloth with hollow tubular fiber units was constructed as the host material for Na plating(Na@CC)to tackle these challenges.The obtained composite electrode can effectively reduce the nucleation overpotential of Na,guide the homogeneous Na^(+)flux,increase the kinetics of Na electrodeposition,lower the effective current density and eventually suppress the formation of electrochemically inactive Na dendrites.As a result,batteries built with the Na@CC composites exhibited stable long-term cycling stability.To gain an in-depth and comprehensive understanding of such phenomena,non-destructive and three-dimensional synchrotron X-ray tomography was employed to investigate the cycled batteries.Moreover,the COMSOL Multiphysics simulation was further employed to reveal the Na electrodeposition mechanisms.The current work not only showcases the feasibility of currently proposed sodiophilic 3 D Na@CC composite electrode but also provides fundamental insights into the underlying working mechanisms that govern its outstanding electrochemical performance.