F-Free Pressure-Sensitive Adhesives as Dry-Coating Process Binders for Ultrahigh-Loading Graphite Anodes

Abstract

High-loading electrode engineering is a cost-effective and practical method of increasing the energy density by minimizing the content of inactive materials in the cell. However, sluggish Li-ion intercalation at the graphite anodes during the charging process results in capacity limitations and cycling deterioration. For the first time, we present herein a pressure-sensitive adhesive (PSA) based on F-free styrene–butadiene rubber (SBR). When subjected to external pressure calendaring at room temperature, PSA-SBR becomes highly sticky, enabling a solvent-free dry-coating process. This approach results in the formation of flexible, freestanding electrode films and creates an open-channel interface on the graphite surface, thereby reducing interfacial resistance. Additionally, it establishes a low-resistance solid electrolyte interphase, particularly when using a fluoroethylene carbonate additive, leading to a stable cell performance with an areal capacity of 10.6 mAh cm^–2. This binder shows potential applicability to other high-loading electrodes with significant interfacial resistances.