In the field of new energy storage, supercapacitors, with their strong instantaneous charge-discharge capability, long cycle life, and excellent low-temperature performance, have become an important supplement to power batteries. Meanwhile, the lithium-ion battery dry process, which has attracted much attention in recent years, not only revolutionizes lithium battery manufacturing but also, with its core logic of "solvent-free and low energy consumption", resonates subtly with the production needs of supercapacitors, opening up a new path for the synergistic development of these two energy storage devices.
The core structure of supercapacitors includes electrodes, separators, and electrolytes, among which electrode preparation is the key link determining their performance. Traditional supercapacitor electrode manufacturing mostly adopts a process similar to the wet process of lithium batteries: mixing activated carbon, conductive agents, binders, etc., into solvents (such as ethanol or water) to form a slurry, which is then coated and dried for shaping. Although the toxicity of solvents in this process is lower than that of NMP used in the lithium battery wet process, there are still three pain points: high energy consumption in the drying link, increased production costs due to solvent recovery, and significant impact of slurry uniformity on electrode conductivity.
The "solvent-free" idea of the lithium-ion battery dry process, however, provides an optimization direction for supercapacitor electrode preparation. Through mechanical mixing (such as high-speed shearing and ball milling), activated carbon particles can be directly fused with binders (such as PTFE and PVDF) to form a dry mixture with a porous structure, which is then roll-formed into electrode sheets. This process not only eliminates solvent procurement and drying costs but also precisely regulates electrode porosity through physical actions. For supercapacitors, the pore structure directly affects charge storage capacity, and the mechanical regulation method of the dry process makes it easier to achieve uniform porous distribution, thereby improving capacitance density and charge-discharge efficiency.
Further Upgrading Cost Control: Although the cycle life of supercapacitors far exceeds that of lithium batteries (up to 1 million cycles or more), their high unit cost limits large-scale applications in energy storage. The dry process eliminates investment in solvents and recovery equipment, shortens the production cycle by more than 20%, and can reduce electrode manufacturing costs by 15%-25%, providing support for "cost reduction and volume expansion" of supercapacitors.
Expanded Material Compatibility: Electrode materials for supercapacitors are evolving from traditional activated carbon to new carbon materials such as graphene and carbon nanotubes, which are often sensitive to solvents (e.g., prone to agglomeration). The dry process avoids solvent-induced damage to material structures through physical mixing, better preserving the high conductivity and large specific surface area of new carbon materials. This helps supercapacitors break through to "high energy density" (currently, supercapacitor energy density is mostly 5-15Wh/kg, and the dry process is expected to push it to over 20Wh/kg).
Synergistic Efficiency in Green Manufacturing: Both supercapacitors and lithium batteries face environmental pressures under the "dual-carbon" goals. The dry process eliminates solvent pollution from the source, reducing carbon emissions in production by more than 40% compared to traditional processes. For enterprises that simultaneously operate lithium battery and supercapacitor production lines, the equipment versatility of the dry process (such as mixing and rolling equipment) enables technology reuse, further reducing the cost of green transformation.
Currently, the application of the lithium-ion battery dry process in supercapacitors is still in the exploration stage, but Tsingyane has verified its feasibility through pilot lines. For example, a supercapacitor with activated carbon electrodes prepared by the dry process in an energy storage enterprise achieved a capacity retention rate of over 90% at -40°C, with performance degradation of less than 5% after 100,000 cycles, and production costs 22% lower than traditional processes.
As technology matures, the dry process may become a "green link" connecting lithium batteries and supercapacitors: in the new energy vehicle sector, lithium batteries handle range, while supercapacitors manage startup and brake energy recovery, and both can share dry process production lines to achieve efficient synergy in manufacturing. In energy storage power stations, supercapacitors produced by the dry process can form hybrid energy storage systems with lithium batteries, meeting both long-term energy storage and instantaneous power regulation needs while reducing the overall system's carbon footprint.
The process iteration from "wet" to "dry" is not only progress in manufacturing technology but also a microcosm of the green and intensive development of the energy storage industry. When supercapacitors meet the lithium-ion battery dry process, these two seemingly independent technologies are sparking a "1+1>2" effect, offering more possibilities for efficient energy storage in the new energy era.
