eScience (Mar 2022)

Electroactive polymeric nanofibrous composite to drive in situ construction of lithiophilic SEI for stable lithium metal anodes

  • Ai-Long Chen,
  • Nan Shang,
  • Yue Ouyang,
  • Lulu Mo,
  • Chunyang Zhou,
  • Weng Weei Tjiu,
  • Feili Lai,
  • Yue-E Miao,
  • Tianxi Liu

Journal volume & issue
Vol. 2, no. 2
pp. 192 – 200

Abstract

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Uncontrolled lithium dendrite growth hinders the practical application of lithium metal batteries (LMBs). Herein, we report a novel Li+ flux distributor achieved by placing an electroactive polyvinylidene fluoride/polymethyl methacrylate (PVDF/PMMA) composite nanofiber interlayer on a current collector, inducing uniform lithium deposition to mitigate the dendrite problem. Specifically, the released PMMA reacts with Li+ to form abundant C–O–Li bonds and generate in situ a stable lithiophilic PMMA-Li solid electrolyte interphase layer. Theoretical calculations reveal that polar C–F groups in the PVDF framework and lithiophilic PMMA-Li provide homo-dispersed Li+ migration pathways with low energy barriers. Consequently, uniform Li nucleation is achieved at the molecular level, resulting in ultrahigh cycling stability with dendrite-free Li deposition at 5 ​mA ​cm−2 and 5 mAh cm−2 for over 500 ​h. The PVDF/PMMA ​∼ ​Li || LiFePO4 (LFP) full cell presents an increased rate capacity of 110 mAh g−1 at 10 ​C. In addition, a soft-package battery demonstrates a high energy density of 289 ​Wh kg−1. This work provides a facile design for stable lithium metal anodes to promote the practical use of LMBs and other alkali metal batteries.

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