摘要
Silicon(Si)anodes offer an ultrahigh theoretical capacity but face two major barriers to commercialization:severe structural degradation caused by significant volume changes and sluggish ion transport kinetics due to the discontinuous ionic conductance of conventional binders.To address these challenges,we develop a fully integrated Si anode using sulfonated graphene(SG)as a dual-functional ion-conductive and mechanical reinforcing framework within a conventional carboxymethyl cellulose/styrene-butadiene rubber(CMC/SBR)binder.Thermally activated reactions during electrode fabrication establish covalent sulfonate ester bonds between SG and CMC,elastic carboxylate crosslinks between SBR and CMC,and chemical anchoring between the binders and Si particles,which are all further reinforced by hydrogen bonding.This multi-bonding network not only dissipates mechanical stress and maintains electronic connectivity via embedded C65 carbon but also significantly enhances Li^(+)transport through high intrinsic ionic conductivity of SG,facilitating the formation of a stable solid electrolyte interphase(SEI).The resulting Si@CMC/SBR/SG anode delivers a high initial capacity of 3513.2 mAh g^(-1)and retains 77%capacity after 500 cycles at 2 A g^(-1).It achieves 762 mAh g^(-1)at 4 A g^(-1)and practical areal capacities exceeding 4 mAh cm^(-2).Full-cell tests with NCM811 cathodes confirm 86.2%capacity retention after 100 cycles.This work demonstrates a pragmatic and scalable integration paradigm for durable,high-energy-density Si anodes.
基金
Opening Project of the National Key Laboratory of Advanced Polymer Materials(Sichuan University)(sklpme2024-1-08)。
