On Accuracy of Porous Electrode Design in the Presence of Negative Effects of Carbon-Binder Networks

Abstract

Porous electrodes for Li-ion batteries are composed of energy storing active material particles, carbon-binder networks, and electrolyte filled pores 1. The carbon-binder networks improve the electronic conduction through the porous electrode, and are expected to improve electrode performance at finite currents. Accordingly, the porous electrode designs treat carbon-binder networks as a positive influence. In this talk, by using systematic experiments of electrochemical performance for different electrode compositions, we will show that the carbon-binder networks also exhibit negative effects 2. These negative effects deteriorate performance by decreasing the area available for intercalation reaction as well as increasing the resistance to ion transport. These effects are prominent for electrodes even with low carbon-binder content, e.g., 5%wt (of dry electrode). We will discuss the implications of these results in the context of predicting porous electrode performance 3, and in turn, designing these electrodes for different operations. Liu et al. (2012) Particles and Polymer Binder Interaction: A Controlling Factor in Lithium-ion Electrode Performance, J. Electrochem. Soc. 159(3), pp. A214-A221, https://doi.org/10.1149/2.024203jes Mistry et al. (2021) Quantifying Negative Effects of Carbon-binder Networks from Electrochemical Performance of Porous Li-ion Electrodes, J. Electrochem. Soc. 168(7), 070536, https://doi.org/10.1149/1945-7111/ac1033 Doyle, Fuller & Newman (1993) Modeling of Galvanostatic Charge and Discharge of Lithium/Polymer/Insertion Cell, J. Electrochem. Soc. 140(6), pp. 1526-1533, https://doi.org/10.1149/1.2221597 Figure 1