Improving the NMC111∣Polymer Electrolyte Interface by Cathode Composition and Processing

Abstract

Despite significant improvements of polymer electrolyte properties, the interfaces towards the electrodes often yield high interfacial resistances due to poor contacts, which are bottlenecks for application of newly developed polymer, ceramic or composite electrolytes in lithium metal batteries (LMBs). Herein, the impact of processing as well as slurry composition of LiNi1/3Co1/3Mn1/3O2 (NMC111) based composite cathodes on the achievable electrochemical C-rate performance of LMBs based on quasi-solid single ion conducting polymer electrolytes (SIPE) is demonstrated. Composite cathodes with varying types and amounts of lithiated species are fabricated and systematically compared. Among all considered electrodes, cathodes with an addition of 5 wt% lithiated terephthalic acid (TA Li) yield the highest discharge capacity of 91 mAhg−1 at 1 C for Li metal∣SIPE∣NMC111 cells. Furthermore, similar cells operated with cathodes whose pores are impregnated with 5 wt% SIPE via drop/spin coating even provide a specific discharge capacity of 113 mAhg−1 at 1 C, thereby clearly highlighting the benefit of the selected processing strategy to realize cathodes with substantially improved charge carrier transport networks.