South Korean Researchers Use Carbon Nitride Additive to Unclog Ion Flow in Thick Dry Battery Cathodes

Researchers led by Dr. San Moon and Dr. Jungdon Suk at the Korea Research Institute of Chemical Technology (KRICT) have developed a dry thick-film cathode architecture that incorporates graphitic carbon nitride (g-C3N4) as an additive to speed lithium-ion transport through dense electrodes. As reported by TechXplore (https://techxplore.com/news/2026-09-lithium-ion-traffic-ease-additive.html), the technique aims to alleviate the transport bottlenecks that typically limit usable capacity in thick, high-energy-density battery electrodes designed for applications like long-range electric vehicles.

Thicker battery electrodes allow manufacturers to pack more active material into a cell while reducing the relative weight and volume occupied by inactive elements such as current collectors and separators. However, standard wet-slurry manufacturing processes require solvents and drying phases during which chemical binders often migrate to the electrode surface, creating uneven internal structures. While dry electrode manufacturing eliminates solvents and avoids binder migration, dense, thick layers still suffer from sluggish lithium-ion transport into deeper regions, causing electrochemical activity to concentrate near the exterior surface and stranding energy capacity inside.

To clear this bottleneck, the research team used porous graphitic carbon nitride as an internal ion guide. Surface nitrogen atoms on the g-C3N4 additive form temporary lithium-nitrogen bonds with passing lithium ions, helping them shed electrolyte solvent molecules and enter the cathode active material. Combined with improved electrolyte wettability from the additive's porous structure, this mechanism enables a more uniform distribution of ions across the electrode.

In laboratory testing, a 68-micrometer-thick dry cathode containing 0.5 weight percent g-C3N4 showed a 56 percent drop in charge-transfer activation energy, falling from 49.8 to 22.1 kilojoules per mole. At a high discharge rate of 3C, the cathode recorded a 165.9 percent increase in discharge capacity, rising from 58.8 to 156.2 milliampere-hours per gram, while boosting power density by up to 2.85 times. In pouch-type full cells, capacity retention after 600 charge-discharge cycles reached 81.3 percent with the additive, compared to 72.9 percent without it.

The authors noted that increasing the additive concentration beyond optimal levels increases overall electrical resistance because graphitic carbon nitride is a poor electrical conductor. Additionally, electrode expansion over time—known as the spring-back effect—can elongate and distort ion pathways. As a result, the authors emphasized that practical implementation requires balancing additive content, spatial placement, and cathode pore structure. The study did not measure commercial production yields or specific unit manufacturing cost reductions.

The research was conducted in collaboration with Seoul National University, Yonsei University, and Thermo Fisher Scientific Korea, with findings published in the journal Exploration.