Performance and Production Advantages of Dry-Process Electrodes for Supercapacitors Compared With Wet-Process Electrodes

Supercapacitors are typical power-type energy storage devices, characterized by millisecond-level rapid response, ultra-high-rate charge and discharge, million-level high-frequency cycling, and stable output under wide temperature ranges. Restricted by solvent coating, high-temperature drying and thermal shrinkage defects, traditional wet electrode processes suffer from inherent drawbacks such as high internal resistance, uneven pore distribution, limited compaction density and rapid performance decay under high-frequency cycling. These shortcomings make wet-process electrodes inadequate for stringent operating scenarios including grid frequency regulation, industrial transient voltage stabilization and vehicle high-frequency power compensation. In contrast, the solvent-free, fully physical dry electrode process fundamentally eliminates the inherent defects of wet manufacturing. It delivers all-round improvements in microstructure optimization, electrochemical performance, cycle stability, production cost control and green manufacturing, becoming a core technical solution for performance upgrading and cost reduction of mass-produced supercapacitors.

1. Optimized Microstructure for Lower Internal Resistance and Higher Power Output

During wet-process production, solvent evaporation generates intense capillary stress, which easily causes micropore collapse, particle agglomeration and internal microcracks, forming disordered pore structures inside electrodes. Such structural defects greatly increase electron and ion transmission resistance, leading to high equivalent series internal resistance, limited instantaneous power output, severe heat generation and significant voltage drop under high-rate operating conditions, restricting the full play of supercapacitors’ power advantages.

Dry-process electrodes involve no solvents or drying-induced thermal shrinkage. Through uniform dry powder mixing, controlled binder fibrillation and constant-temperature precision calendering, a uniform, interconnected and stable three-dimensional porous conductive network is constructed. The internal pores are regularly arranged without structural collapse or residual stress, forming continuous and unobstructed conductive paths that effectively reduce the internal resistance of supercapacitors. Lower internal resistance minimizes voltage drop and heat loss during charge and discharge, endowing supercapacitors with stronger instantaneous power throughput. This technology perfectly adapts to core application scenarios such as high-frequency grid frequency regulation, instantaneous equipment energy supplement and pulse power output, delivering a substantial improvement in power density compared with wet-process solutions.

2. Breaking Compaction Density Limits to Boost Energy Density and Loading Capacity

Wet-process electrodes have a natural ceiling in compaction density. High-pressure compaction commonly causes pore blockage, electrode brittleness and delamination, making high-areal-density and high-loading electrode forming unachievable and severely restricting the energy density improvement of supercapacitors. Against the trend of miniaturization and lightweight terminal devices, wet processes cannot balance power performance and energy capacity.

Featuring zero thermal deformation and excellent structural toughness and integrity, the fully physical dry forming process supports high-precision ultra-high-pressure calendering. It greatly improves electrode compaction density and active material loading while retaining effective ion transmission pore channels, solving the long-standing dilemma of wet processes — pore blockage under high compaction and low capacity under low compaction. This upgrade increases single-cell capacity and energy density without sacrificing power performance, enabling miniaturized and integrated design for high-end industrial, automotive and energy storage equipment. Practical tests verify that dry processing improves the energy density of supercapacitors by approximately 30% and comprehensively optimizes overall loading performance.

3. Zero Solvent Residue for Doubled Cycle Life and Superior Stability

Wet processes inevitably leave trace solvent residues inside electrodes. These residual impurities trigger continuous side reactions during million-level high-frequency cycling, corroding electrode interfaces, blocking micropore channels, causing rapid capacity attenuation and progressive internal resistance rise — the key factors limiting the cycle life and batch consistency of wet-process supercapacitors. The performance decay issue is particularly prominent in grid-side 24/7 high-frequency charge-discharge operating conditions.

Dry-process electrodes achieve zero solvent residue and zero impurity contamination from the source, maintaining ultra-clean and stable electrode interfaces without chemical attenuation during long-term operation. Meanwhile, the flexible network formed by fibrillated binders effectively buffers particle expansion and contraction during high-frequency cycling, preventing structural collapse and powder shedding. Compared with wet-process products, dry-process supercapacitors deliver significantly enhanced cycle stability and doubled overall cycle life. They stably support over one million high-frequency charge-discharge cycles with extremely low long-term capacity decay, fully meeting the long-cycle and high-reliability requirements of power energy storage and industrial equipment applications.

4. Superior Wide-Temperature Adaptability for Harsh and Complex Operating Conditions

Supercapacitors are widely deployed in harsh scenarios including outdoor power grids, vehicle systems and special industrial equipment, which require stable operation under wide temperature fluctuations, high humidity and strong vibration. Due to uneven internal pores and water absorption caused by residual solvents, wet-process electrodes suffer from severe parameter drift, internal resistance fluctuation and performance degradation under extreme temperatures, resulting in insufficient operational reliability.

Dry-process electrodes feature a dense and uniform structure, ultra-low water absorption and zero solvent residue, maintaining stable structural integrity and consistent electrical performance under temperature variations. Their dielectric parameters, internal resistance and capacity retention rate remain highly stable across operating environments. With superior low-temperature startup performance and excellent high-temperature anti-attenuation and moisture resistance, dry-process electrodes enable all-weather and full-scenario stable operation, greatly improving the environmental adaptability and operational reliability of supercapacitor terminal products.

5. Streamlined Manufacturing for Cost Reduction and Eco-Friendly Mass Production

Wet-process supercapacitor production involves lengthy and complex procedures, including slurry mixing, high-temperature drying, solvent recovery and waste gas and liquid treatment, which require massive equipment investment, high energy consumption and substantial environmental costs, while generating high defective product rates. In contrast, dry processing completely eliminates solvent usage and high-temperature drying procedures, greatly simplifying the production workflow. It significantly reduces fixed asset investment, energy consumption and carbon emissions, eliminates VOC emissions, and fully complies with global low-carbon and green manufacturing standards.

Furthermore, dry electrode forming delivers higher yield rates and better batch consistency without common defects such as powder shedding, cracking and warpage. It effectively reduces rework loss and later operation and maintenance costs, realizing dual advantages of performance upgrading and cost reduction for supercapacitors and demonstrating outstanding scalability for large-scale industrial production.