Conductive Polymer Frameworks in Silicon Anodes for Advanced Lithium-Ion Batteries

Abstract

Silicon anode is endowed with a high theoretical specific capacity. Unfortunately, its applicability in lithium-ion batteries is hindered by several inevitable problems, which are associated with volume changes (i.e., particle pulverization, solid electrolyte interphase layer instability, and electrode failure) and low electrical conductivity of silicon. Among the accessible strategies to enhance the anode performance, conductive polymer frameworks have been envisioned as solutions to overcome the problems. Conductive polymers can jointly bind and electronically connect silicon particles to regulate extensive volume changes while providing pathways for charge transport in a low-cost fashion. This review starts with a detailed summary of conductive polymer framework features in silicon anodes. The main section presents an in-depth discussion and current advancements of the most widely used conductive polymers in silicon anodes [i.e., polyfluorene, polyaniline, polypyrrole, polythiophene, and poly(3,4-ethylenedioxythiophene)] and several other conductive polymers. In the penultimate part, we review the performance evaluation of silicon anodes with five main conductive polymers and provide perspectives on future challenges of batteries from the standpoint of device manufacturing scale-up. In the final part, we briefly summarize the discussed advancements of conductive polymer frameworks in silicon anode for lithium-ion batteries.

Para Grass-Derived Porous Carbon-Rich SiOx/C as a Stable Anode for Lithium-Ion Batteries

“…Silicon-based anodes are an attractive option for lithium-ion batteries (LIBs) owing to their large theoretical specific capacity (∼4200 mAh g –1 ), acceptable operating voltage (discharge voltage of 0.4 V vs Li/Li + ), and a wide range of available precursors. − However, a significant volumetric change of up to 380% takes place during lithium ion insertion and extraction into and from silicon, resulting in activity loss and instability during cycling. − Compared to pristine silicon, silicon oxide (SiO x ) has smaller volume expansion (160–200%), simpler synthesis procedures, and lower production cost but a smaller theoretical capacity (2680 mAh g –1 ). , During the initial lithiation process, SiO x generates inert Li 2 O and lithium silicates (Li 4 SiO 4 , Li 2 Si 2 O 5 ) that serve as a buffer during volume changes and assist in sustaining its structural integrity. ,,, …”

Si-based Anode Lithium-Ion Batteries: A Comprehensive Review of Recent Progress

“…Because of its internal isotropic stresses, amorphous silicon prevents more structural fractures during the lithiation/delithiation processes . Moreover, the working potential of amorphous Si (∼0.22 V vs Li/Li + ) is higher than that of crystalline silicon (∼0.12 V vs Li/Li + ), which not only facilitates the suppression of lithium dendrite generation but enhances the cycling stability of the anode material . For example, Lin et al synthesized mesoporous amorphous Si powders by a solvothermal reaction and subsequent high-temperature annealing which has SiO x covering its surface (Figure A).…”