Hierarchically Structured Conductive Polymer Binders with Silver Nanowires for High-Performance Silicon Anodes in Lithium-Ion Batteries

Abstract

Silicon (Si) anodes in lithium-ion batteries (LIBs) suffer from huge volume changes that lead to a rapid capacity decrease and short cycle life. A conductive binder can be a key factor to overcome this issue, maintaining continuous electron paths under pulverization of Si. Herein, composites of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and poly(vinyl alcohol) (PVA) are augmented with poly(ethylene glycol) (PEG) and poly(ethylene oxide) (PEO) as a binder for Si anodes, which forms hierarchical structures due to different chain lengths of PEG and PEO. The integration of PEG and PEO imparts higher electrical conductivity (∼40%) and stretchability (∼60%) through densely spread hydrogen bonding and crosslinking, compared to conductive polymer binders with PEO or PEG. Further, a silver nanowire (AgNW) network combined with the polymer binder supplies an effective three-dimensional (3D) electrical path, sufficient void space to buffer the volume changes, and highly adhesive interaction with the current collector. The fabricated Si anode demonstrates a higher specific capacity of 1066 mAh g −1 at 0.8 A g −1 after 100 cycles and improved rate capability.

Room-Temperature Rapid Self-Healing Polymer Binders for Si Anodes in Highly Cycling-Stable and Capacity-Maintained Lithium-Ion Batteries

“…10,42−44 Ionically and electronically conductive polymers (c-PEOPEDOT:PSS/PEI) have also been widely studied for high-performance Si anodes. 45 However, these polymers cannot assist in preserving the integrity of Si particles in anodes, especially when they undergo severe volume change during repeated charging/discharging processes. Consequently, self-healing binders were proposed for their capability of suppressing the volume expansion of Si particles and rapidly impairing the deterioration of anodes.…”

One-step fabrication of highly stable, durable, adhesion enhanced, flexible, transparent conducting films based on silver nanowires and neutralized PEDOT:PSS

“…), binders (PVA, PDMS, epoxy) and overcoating (conductive polymer/silica binder) which overcame certain drawbacks of AgNW TCFs. 7,[57][58][59][60][61][62][63][64][65][66][67][68] However, the reliability and mechanical stability of AgNW TCFs remain an important issue. AgNW TCF fabrication with hybrid approaches and post-processing (thermal annealing, mechanical pressing, and protective layer overcoating) which are done in multiple steps would also increase the manufacturing cost and restrict scalable fabrication for commercial applications.…”

Multifunctional Thermally Conductive Composite Films Based on Fungal Tree‐like Heterostructured Silver Nanowires@Boron Nitride Nanosheets and Aramid Nanofibers

“…However, the preparation of hetero‐structured AgNWs@BNNS thermally conductive fillers by growing BNNS on the surface of AgNWs has not yet been reported. On one hand, the growth of BNNS on the surface of AgNWs needs strong force to maintain the stability of the composite system due to the large aspect ratio and high surface curvature of AgNWs [46–48] . On the other hand, it is challenging to precisely control the optimal morphology of hetero‐structured AgNWs@BNNS thermally conductive fillers because there is no reported technology for orientation or uniform distribution that can be utilized as guidance [49–51] …”

“…On one hand, the growth of BNNS on the surface of AgNWs needs strong force to maintain the stability of the composite system due to the large aspect ratio and high surface curvature of AgNWs. [46][47][48] On the other hand, it is challenging to precisely control the optimal morphology of heterostructured AgNWs@BNNS thermally conductive fillers because there is no reported technology for orientation or uniform distribution that can be utilized as guidance. [49][50][51] The advantages of aramid nanofibers (ANF) include lightweight, high specific strength, and good high-temperature resistance, [52,53] as well as its ability to maintain outstanding mechanical and electrical insulating properties in situations with both high and low temperature and humidity.…”