锂负极保护层的原位构筑及界面调控研究OA

To address key challenges associated with lithium metal anodes in high-energy-density batteries,including severe dendrite growth,unstable solid electrolyte interphase(SEI),and substantial volume expansion,in this study,we proposed a simple and efficient in situ photopolymerization strategy——a protective layer(PL)was constructed in situ on the lithium metal anode surface using poly(ethylene glycol)diacrylate(PEGDA)and lithium bis(trifluoromethanesulfonyl)imide(LiTFSI).Characterization via Fourier transform infrared spectroscopy and scanning electron microscopy confirmed that the PL effectively accommodated volume changes during lithium plating/stripping and enhanced the stability of the electrolyte/anode interface.Moreover,the PL inhibited disordered lithium dendrite growth and blocked continuous side reactions between the electrolyte and active lithium.Electrochemical evaluations revealed that the PL effectively reduced nucleation overpotential and local current density,thereby promoting uniform and stable lithium plating/stripping.Symmetric Li||Li cells incorporating the PL achieved stable cycling for over 1 200 h,exhibiting excellent stability.And full cells assembled with LiFePO4 cathodes retained 95％of their initial specific capacity after 300 cycles at 1.0 C and maintained a high discharge specific capacity even at a high rate of 4.0 C.