Tailoring the Lithium Deposition on Cu Substrate by a Functionalized-Polysiloxane Layer

Abstract

Owing to the high theoretical capacity of 3860 mAh g⁻¹ and low redox potential, lithium metal is the best candidate for the development of next generation high-energy density lithium-ion batteries. However, notorious lithium dendrites growth and the poor compatibility of liquid electrolyte hinder the commercialization of lithium metal batteries. In this work, an anode-less system was used to understand the change in lithium deposition on Cu current collector after the additional functionalized-polysiloxane (PE) layer. The PE structure consists of lithiophobic and lithiophilic side chains which facilitate the uniform lithium deposition on Cu substrate. This evidence was collected by scanning electron microscopy (SEM) after the cycling test of half-cell configuration and the lithium deposition with different current densities. The reversibility was improved by 5 % compared with the bare Cu. In addition, the potential polarization was lowered after the addition of PE layer on bare Cu. Thus, the higher cycle stability (40 %) and more stable coulombic efficiency are observed on the PE@Cu||NCM83 cell compared with the bare-Cu||NCM83 during the cycle test.