Graphite Dry Electrode (Disc, Sheet) with High Loading (18.9-27.4 mg/cm2) for Li-Ion Battery, CLIBDEHLG

Creating a high-loading graphite dry electrode for lithium-ion batteries (LIB) is a critical step in reducing manufacturing costs and increasing energy density. By eliminating the solvent-drying step, you can produce electrodes that are much thicker than traditional wet-coated ones without the risk of cracking or "binder migration" (where the binder floats to the surface, leaving the bottom of the electrode brittle).

Graphite particles are typically flaky or spherical (mesocarbon microbeads). Unlike polyanion cathodes, graphite is relatively soft but has a slippery surface. (1) Binder Choice: PTFE (Polytetrafluoroethylene) is the standard for dry electrodes. For high loading, a concentration of 3–6% PTFE is typical. (2) Shear Force: High-shear mixing (using a jet mill or a high-speed cyclomix) is required to "tease out" the fibrils from the PTFE granules. These fibrils act as a microscopic web that traps the graphite particles.

In traditional wet coating, thick electrodes often peel off the copper foil during drying. Dry processing solves this, but introduces new variables: (1) Electrode Thickness: Dry processing easily achieves thicknesses of 200 μm to 500 μm. However, at these levels, ion transport becomes the bottleneck. (2) Vertical Pore Engineering: High-loading graphite can become too dense during calendering, leading to high tortuosity (a "winding path" for ions). You must balance the calendering pressure to maintain a porosity of 25–35% to allow the electrolyte to penetrate the full depth of the electrode. (3) Conductive Additives: While graphite is conductive, adding 0.5–1% Carbon Nanotubes (CNTs) is highly recommended for high loadings. CNTs bridge the gap between graphite flakes more effectively than Carbon Black, ensuring a stable electronic path throughout the thick sheet.

Graphite Dry Electrode can be used as sodium-ion battery cathode. The round disc shape with single-side coating is suitable for coin cell testing, while the rectangle sheet shape with single- or double-side coating is designed for single-layer or multiple-layer pouch cell testing.

Notes: (1) Please store the graphite electrodes in a dry area (glovebox is preferred); (2) The battery electrodes are highly recommended to be dried at 80-100°C in a vacuum oven for 6-12 h before use. 

References: 

1. Z. Wei, et al. Removing electrochemical constraints on polytetrafluoroethylene as dry-process binder for high-loading graphite anodes, Joule, 2024, 8, 1350-1363.
2. D. R. Kim, et al. Morphology-engineered, randomly oriented graphite granules enabling PTFE-free dry anode process with enhanced lithium-ion transport,Energy Storage Materials, DOI: 10.1016/j.ensm.2026.105149.