New Tech Boosts EV Range, Cuts Battery Costs

Abstract

Dry-processed thick electrodes are a key strategy for increasing the energy density of batteries. However, thick dry electrodes, especially anodes, suffer from limited ion mobility, causing non-uniform solid-electrolyte interphase (SEI) formation and high irreversible capacity loss during the initial cycle. Moreover, the adhesive primer layer required during processing increases electrical resistance and necessitates additional wet-processing steps, thereby undermining both performance and process integrity. To address these issues, we propose an underlayer lithium-metal-configured prelithiation strategy for thick electrodes. Here, a lithium metal underlayer simultaneously functions as a primer, compensates for irreversible lithium loss during the initial cycle, and promotes uniform SEI formation through a chemical reaction. Consequently, this strategy enhances the initial coulombic efficiency and cycle stability of high-energy-density silicon-graphite/NCM811 full-cells. By overcoming the limitations of the conventional dry process, a fully dry manufacturing process is enabled and advances the development of next-generation high-energy-density batteries.

A research team affiliated with UNIST has unveiled a novel dry-process manufacturing method for thick electrodes aimed at enhancing electric vehicle (EV) driving range while reducing battery production costs.

Professor Won-Jin Kwak of the School of Energy and Chemical Engineering at UNIST, in collaboration with Professor Junghyun Choi of Gachon University and Professor Janghyuk Moon of Chung-Ang University, announced that they have successfully overcome key challenges associated with thick, dry-processed electrodes-specifically initial capacity loss and manufacturing complexity.

Thick electrodes, which increase battery capacity by enlarging the active material layer, are considered a promising direction for next-generation batteries. Unlike traditional electrodes, they are produced via a dry process that eliminates toxic solvents, making them environmentally friendly. However, a major obstacle has been significant capacity loss during the first charge-discharge cycle, mainly due to the thick active material layer and binder used to hold dry particles together.

Figure 1. Comparison of prelithiation methods with factors for practical application.

The research team introduced a pioneering approach: inserting a thin lithium-metal film between the anode's active material layer and the copper current collector, replacing the conventional primer layer. Typically, primers are used to improve adhesion, but this lithium-metal film serves a dual purpose. It acts as an adhesion layer and pre-supplies lithium, compensating for the inevitable lithium loss during initial cycling. Driven by electrochemical potential, lithium atoms migrate from the film into the active material, significantly reducing capacity loss.

Experimental results showed that batteries with these advanced dry thick electrodes experienced approximately 75% less initial capacity loss compared to conventional counterparts. This improvement translates into a roughly 20% increase in EV driving range. Furthermore, the new approach streamlines manufacturing by removing the need for separate wet-chemical primer coating and drying steps, often required in traditional processes.

Hyun-Wook Lee, the first author and researcher at UNIST, explained, "This technique allows us to perform prelithiation and electrode adhesion in a single, efficient process that can be directly integrated into existing roll-to-roll manufacturing-similar to how newspaper presses operate, enabling large-scale production."

Professor Kwak added, "Dry-electrode coating technology is an area actively pursued by global companies like Tesla. Our developed anode technology is compatible with various cathode materials, including high-nickel cathodes, and offers a competitive advantage in the rapidly evolving battery industry."

The findings of this research have been published online in Energy & Environmental Science on January 21, 2026. This study has been supported by the Technology Innovation Program, funded by the Ministry of Trade, Industry & Energy (MOTIE).

Journal Reference

Hyun-Wook Lee, Woojin Jeong, Seongsoo Park, et al., "Integrated one-step dry process enabling prelithiated thick electrodes without primer coating for high energy density and initial coulombic efficiency," Energy Environ. Sci., (2026).