Scalable Dry Processing of Binder-Free Lithium-Ion Battery Electrodes Enabled by Holey Graphene

Abstract

To address the multitude of issues that accompany wet electrode fabrication techniques, composite lithium-ion battery (LIB) electrodes composed of solely active components (active battery material and conductive additive) are fabricated using a scalable and eco-friendly dry processing method known as dry pressing. To accomplish this, a nanoporous carbon allotrope (i.e., holey graphene or hG) acts as the compressible and conductive matrix to accommodate incompressible cathode and anode battery powders. The inherent nanoporosity facilitates the escape of trapped gases upon compression, enabling the successful formation of binderless and solventless composite electrodes independent of selected active battery powder, fabrication pressure, or pressing time. Dry pressed LIB electrodes fabricated with different processing parameters (e.g., hydraulic pressure, pressing time) are evaluated structurally and electrochemically using a model cathode material (lithium iron phosphate, LFP) in order to demonstrate the potential of dry pressing as a viable LIB electrode manufacturing method.