Molecular Spring Enabled High-Performance Anode for Lithium Ion Batteries.

Tianyue Zheng,Isaac Lund,Gao Liu,Ann-Christin Gentschev,Juan Qiao,Simon Lux,Thorsten Langer,Na Lin,Zhe Jia

doi:10.3390/polym9120657

Abstract

Flexible butyl interconnection segments are synthetically incorporated into an electronically conductive poly(pyrene methacrylate) homopolymer and its copolymer. The insertion of butyl segment makes the pyrene polymer more flexible, and can better accommodate deformation. This new class of flexible and conductive polymers can be used as a polymer binder and adhesive to facilitate the electrochemical performance of a silicon/graphene composite anode material for lithium ion battery application. They act like a “spring” to maintain the electrode mechanical and electrical integrity. High mass loading and high areal capacity, which are critical design requirements of high energy batteries, have been achieved in the electrodes composed of the novel binders and silicon/graphene composite material. A remarkable area capacity of over 5 mAh/cm2 and volumetric capacity of over 1700 Ah/L have been reached at a high current rate of 333 mA/g.

Highlights

Lithium-ion batteries (LIBs) have emerged as a critical electrical energy storage solution in consumer electronics, transportation and stationary storage [1,2,3]
We developed two new conductive polymer binders—Poly(1-pyrenebutyl methacrylate) (PBuPy) and Poly(1-pyrenebutyl methacrylate-co-methacrylic acid) PBuPyMAA
Molecular weights and distributions of polymers were measured by Gel permeation chromatography (GPC) with tetrahydronfuran (THF) eluent and polystyrene standard, using a Waters Associates liquid chromatography equipped with a Waters 510 HPLC pump and a Waters 2998 PDI detector

Summary

Introduction

Lithium-ion batteries (LIBs) have emerged as a critical electrical energy storage solution in consumer electronics, transportation and stationary storage [1,2,3]. The lithium-ion battery electrodes consist of nano to micron-sized ceramic particles for lithium ion storage, which are laminated together with a few percent of polymer binders. These electrode laminates need to be both electronically and ionically conductive throughout the battery lifetime. The degradation of the adhesive properties of the polymer in the electrode causes the decay of the both the mechanical and electrically integrity of the electrode, leading to battery capacity fade. The current quest for higher energy density and longer battery operational lifetime has driven the development of new multifunctional polymer binder materials for emerging new energy storage chemistry

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Conclusion