New Electrode Architecture for High Performance Lithium Ion Batteries

Abstract

Lai et al. demonstrated an alternative sintered electrode architecture to conventional powder-based electrodes that improves the energy density over existing lithium ion batteries. By eliminating electrochemically-inert additives, and achieving lower pore tortuosity, this new architecture permits higher density, greater thickness electrodes that increase the volumetric and gravimetric utilization of active material at the cell level. As electrode thickness increases and pore fraction decreases, transport in the pore phase becomes limiting. In order to maximize rate capability at any given electrode thickness and density, tailoring the pore topology is a useful approach. In this work, a new approach to maximize power will be theoretically and experimentally presented using an ordered, dual-scale porosity distribution in the dense, thick electrodes targeting high energy density. In comparison to controls of homogeneous porosity, discharge timescales are reduced by a factor of 2-3, yielding an attractive combination of thickness, density and rate performance, with ~80% of capacity delivered at 2C in electrodes with areal capacity exceeding twice the value for conventional lithium-ion electrodes. Additionally, co-extrusion printing processing technique, commercially produces battery electrodes with ordered, dual-scale porosity distributions, will be introduced.