A Major Upgrade in Efficiency: Process Breakthroughs in Dry-Process Supercapacitors

In the field of supercapacitor production, lithium-ion battery dry process technology is gradually emerging, demonstrating a series of significant advantages compared to traditional wet-process supercapacitor preparation technologies.

From the perspective of preparation processes, the wet-process for supercapacitor preparation is relatively complex. First, active materials, conductive agents, binders, and other components are mixed with solvents to form a slurry. This process requires precise control of the proportion of each component and mixing conditions to ensure the uniformity and stability of the slurry. Subsequently, the slurry is coated onto the current collector, followed by drying to remove the solvent. However, during drying, solvent volatilization may cause issues inside the electrode, such as uneven distribution of active materials—some areas have excessively high or low concentrations of active materials—thereby affecting capacitor performance. Moreover, the use and recycling of solvents not only increase equipment costs but also bring environmental pressures.

In contrast, the most distinctive feature of lithium-ion battery dry process technology is the abandonment of solvents. It directly mixes positive/negative active materials, conductive agents, and binders, then uses specific processes (e.g., fibrillating the binder under high shear force) to press the mixture into films and attach them to the current collector. The entire process eliminates coating and drying steps, greatly simplifying production links. Tsingyane’s dry electrode process, from powder to electrode, skips slurry casting, drying, and rolling. Instead, it fibrillates the powder and polymer materials through a special method, presses them into films, and composites them with current collectors coated with back glue—no liquid substances are introduced throughout the process. This makes production more concise and efficient while avoiding a series of problems caused by solvents.

In terms of performance, supercapacitors produced using lithium-ion battery dry process technology outperform wet-process capacitors in several key indicators. In terms of energy density, the dry process enables tight bonding of electrode components, forming a denser structure that effectively increases electrode compaction density—creating conditions for higher energy density. For example, some supercapacitors prepared using dry technology have an energy density that is more than 20% higher than that of wet-process capacitors. In terms of cycle life, dry electrodes have stronger adhesion and higher flexibility. In wet processes, binders adhere to the surface of active materials over a large area; during charge-discharge cycles, as active materials undergo volume changes, the adhesion between binders and active materials may decrease, leading to damage to the electrode structure and reduced cycle life. In dry processes, however, binders and conductive agents form an adhesive conductive network distributed between active material particles, which can better adapt to the volume changes of active materials, giving the electrode a longer cycle life. Data shows that after 10,000 cycles, the capacity retention rate of dry electrodes can reach 92%, compared to only 87% for wet electrodes. In terms of conductivity, electrodes prepared by dry processes have a larger effective surface area of electrode materials not covered by binders, facilitating ion intercalation/extraction and resulting in better conductivity. In practical applications, this means the capacitor can charge and discharge more quickly, meeting the needs of scenarios with high power requirements.

From a cost-effectiveness perspective, lithium-ion battery dry process technology has obvious advantages. On one hand, it eliminates costs related to solvent procurement, investment in solvent recovery equipment, and significant energy consumption during drying, substantially reducing production costs. According to relevant research, the dry process can reduce production costs by approximately 20%, and equipment investment is 35% lower than that of wet processes. On the other hand, due to performance improvements in supercapacitors produced by dry technology—such as longer cycle life—the frequency of equipment replacement is reduced, lowering overall costs from a long-term usage perspective.

In terms of environmental protection, solvents used in wet-process supercapacitor preparation, such as N-methylpyrrolidone (NMP), are mostly toxic. Their volatilization and wastewater discharge can pollute the environment. In contrast, lithium-ion battery dry process technology uses no solvents at all, avoiding the emission of toxic and harmful substances from the source and representing a more environmentally friendly production method.

Supercapacitors produced using lithium-ion battery dry process technology, with advantages in process, performance, cost, and environmental protection, are gradually becoming an important development direction in the field of supercapacitor production. They are expected to be more widely applied in numerous fields such as energy storage, transportation, and industrial equipment, driving technological upgrading and sustainable development in related industries.