Thermal-Assisted Dry Coating Electrode Unlocking Sustainable and High-Performance Batteries

Adv Mater. 2024 Nov 24:e2410974. doi: 10.1002/adma.202410974. Online ahead of print.

Abstract

Current battery production relies on the use of large amounts of N-methyl-2-pyrrolidnone (NMP) solvent during electrode preparation, which raises serious concerns in material cost, energy consumption, and toxicity, thus demanding the innovation of dry electrodes with excellent performance. However, state-of-the-art dry electrodes show inferior energy densities, particularly under high-areal-capacity and fast charge/discharge conditions required for practical applications. Here dry production of high-energy-density Li- and Mn-rich (LMR) cathodes is shown based on a thermal-assistant approach. The lithium difluoro(oxalate)borate (LiDFOB) and succinonitrile (SN) serve as two key electrode mediators to facilitate Li+ transport, and the mild heating process for melting SN-LiDFOB has significantly improved the distribution of various components in the electrode. These synergistic effects enable dry LMR cathodes with a maximum rate capability of 4 C (12 mA cm-2) and an areal capacity of 11.0 mAh cm-2. The resulting Li metal/LMR full cell exhibits the maximum energy and power densities of 609 Wh kg-1 and 2,183 W kg-1, respectively, based on the total mass of the cathode and anode. These results not only break through the key bottleneck in energy density for dry electrodes but, in a broader context, open a new avenue for green and sustainable battery production.

Keywords: Li metal battery; Li‐ and Mn‐rich cathode; dry coating electrode; electron transport; sufficient Li+; thermal‐assistant distribution.