Beyond Lithium-Ion Batteries: New Application Scenarios of Dry-Process Electrodes in Supercapacitors

When dry-process electrodes are mentioned, most people first associate them with breakthroughs in fast charging and cost reduction for lithium-ion batteries. However, as supercapacitors evolve toward "higher energy density and wider application scenarios," dry-process electrodes—with their unique advantages of "no solvent residue and precisely controllable structure—are emerging as a key force in breaking the application bottlenecks of supercapacitors. From upgrading energy recovery in rail transit to ensuring instantaneous power supply for industrial equipment, and even revolutionizing battery life in consumer electronics, dry-process electrodes are opening up new scenarios for supercapacitors one after another, redefining their value in the energy storage field.

I. Rail Transit: From "Single Energy Recovery" to "Full-Condition Energy Saving," Dry-Process Electrodes Boost Supercapacitor Efficiency

Supercapacitors have long been used in rail transit, but products made with traditional wet-process electrodes have been limited to the single scenario of "braking energy recovery" due to their limited energy density and short cycle life. The introduction of dry-process electrodes, however, has enabled supercapacitors to move beyond "single energy recovery" to achieve "full-condition energy saving."

Supercapacitors made with traditional wet-process electrodes suffer from collapsed electrode micropores due to solvent evaporation, which restricts their specific surface area. As a result, they can only store braking energy for short periods and cannot meet the power demands of trains during startup or climbing. In contrast, dry-process electrodes, through dry mixing and precision calendering, create a hierarchical pore structure of "macropores for energy storage and micropores for mass transfer." Combined with a high-efficiency conductive network, this structure significantly improves the energy density of supercapacitors while maintaining excellent high-power performance.

In the renovation project of a city’s light rail system, trains equipped with dry-process electrode supercapacitors achieved full-condition participation in "braking energy recovery, startup assistance, and climbing power supplementation": during braking, the supercapacitors quickly capture most of the kinetic energy; during startup, they rapidly release electrical energy to assist traction, reducing the power load on the grid; during climbing, they provide real-time power supplementation to prevent trains from slowing down due to insufficient power. After the renovation, the daily energy consumption of trains on this line decreased significantly, and maintenance costs dropped substantially. Additionally, the solvent-free nature of dry-process electrodes allows supercapacitors to maintain stable performance even in low-temperature environments, making them perfectly suitable for rail transit needs in cold northern regions.

II. Industrial Energy Storage: From "Emergency Backup" to "Dynamic Peak Shaving," Dry-Process Electrodes Expand Supercapacitor Application Dimensions

In industrial scenarios, supercapacitors were once only used as "emergency backup power sources" to handle sudden power outages for equipment, due to their high internal resistance and poor adaptability. However, by optimizing electrode interface properties and structural stability, dry-process electrodes have enabled supercapacitors to gain "dynamic peak shaving" capabilities, making them a "new supporting role" in industrial energy storage.

Industrial equipment such as CNC machine tools and robotic arms generate instantaneous power fluctuations during high-frequency startup and shutdown, which destabilizes grid voltage and affects the precision of machining. Traditional wet-process electrode supercapacitors, with their high interface impedance and slow response speed, cannot suppress these fluctuations in a timely manner. Dry-process electrodes, on the other hand, use dry binders compatible with electrolytes and achieve tight bonding between electrodes and current collectors through high-temperature calendering, significantly reducing interface impedance and shortening response time.

In an automobile parts manufacturing plant, dry-process electrode supercapacitors, together with the power grid and equipment, form a "dynamic peak shaving system": when robotic arms generate power peaks during high-frequency startup and shutdown, the supercapacitors instantly release electrical energy to offset the peak load; when the equipment is in a low-load state, they quickly absorb and store excess electrical energy from the grid. After implementation, the grid voltage fluctuation range in the plant was significantly reduced, the qualification rate of precision parts machining increased, and the need for grid expansion was eliminated, saving the plant a large amount of investment in power renovation. Furthermore, the long cycle life of dry-process electrode supercapacitors means they do not need frequent replacement in 24/7 industrial operating scenarios, further reducing maintenance costs.

III. Consumer Electronics: From "Auxiliary Power Supply" to "Main Power Source," Dry-Process Electrodes Reshape Supercapacitor Product Form

In the consumer electronics field, supercapacitors—with their fast charging and high safety features—were once used as "auxiliary power supplies" for devices such as smart watches and headphones. However, limited by their energy density, they could not replace lithium-ion batteries as the main power source. Through "thinning and flexible" design, dry-process electrodes have enabled supercapacitors to achieve breakthroughs as "main power sources" in scenarios such as wearable devices and wireless sensors.

Supercapacitors made with traditional wet-process electrodes are thick and rigid due to process limitations, making them incompatible with the flexibility requirements of wearable devices. Dry-process electrodes, using "ultra-thin calendering technology," can greatly reduce electrode thickness. When combined with flexible current collectors, they form bendable "thin-film supercapacitors" that maintain stable performance even after multiple bends. At the same time, the improved energy density brought by dry-process electrodes allows thin-film supercapacitors to meet the multi-day battery life needs of smart bracelets, with fast charging capabilities that solve the pain points of traditional lithium-ion batteries, such as "slow charging and vulnerability to extrusion."

In a new smart bracelet model from a brand, dry-process electrode thin-film supercapacitors replaced traditional button batteries, achieving "fast charging and long battery life" while offering waterproof and anti-drop features, and significantly reducing the device weight. Additionally, in the field of wireless sensors, dry-process electrode supercapacitors can be paired with thin-film solar cells to absorb and store solar energy during the day and power the sensors at night, eliminating the need for frequent battery replacement. This makes them suitable for scenarios such as environmental monitoring in remote areas and agricultural IoT, greatly reducing deployment and maintenance costs.

IV. Technological Synergy: "Mutual Adaptation" Between Dry-Process Electrodes and Supercapacitors Drives Continuous Scenario Expansion

The adaptation of dry-process electrodes to supercapacitors is not a one-way process upgrade, but a "material-structure-scenario" mutual synergy. On one hand, the solvent-free process and structural controllability of dry-process electrodes solve the core pain points of supercapacitors, such as low energy density, high internal resistance, and poor adaptability. On the other hand, the demand for high power, long life, and wide temperature range in supercapacitors also drives the continuous iteration of dry-process electrode technology—such as specialized processes developed for low-temperature scenarios and ultra-thin electrode technologies for flexible needs.

In the future, with further breakthroughs in the compatibility of dry-process electrodes with active materials and the consistency of large-scale production, supercapacitors are expected to be applied in more scenarios: in the new energy vehicle field, they can form a "hybrid energy storage system" with lithium-ion batteries to handle startup and braking energy recovery, extending the life of lithium-ion batteries; in the energy storage station field, they can serve as "frequency modulation auxiliary power sources" to quickly respond to grid frequency fluctuations; in the aerospace field, their high reliability and long life can provide emergency power for satellites and spacecraft.

From rail transit to industrial energy storage, and then to consumer electronics, dry-process electrodes are opening a "scenario door" for supercapacitors. They not only prove that supercapacitors are not "niche energy storage devices" but also demonstrate the application potential of dry-process technology as a general-purpose technology across energy storage fields. With the deepening of collaborative innovation between the two, supercapacitors will no longer be a "supplement" to lithium-ion batteries, but a "core force" that works in tandem with lithium-ion batteries to support the diversified needs of new energy storage.