Dry Process Technology for Lithium-Ion Batteries: Core Code from Process Innovation to Performance Leap

Amid the new energy industry's march toward "higher energy density, faster charging, longer lifespan, and lower energy consumption," innovations in lithium-ion battery (LIB) manufacturing processes have become critical to breaking performance barriers. The traditional wet electrode process relies on core steps such as organic solvent mixing and high-temperature drying, which not only drive up production costs and carbon footprints but also limit the release of LIBs' core performance due to microstructural defects in electrodes caused by solvent evaporation. Dry process technology, centered on the principles of "solvent-free production and precise film formation," not only reconstructs the LIB manufacturing workflow but also achieves significant breakthroughs in key indicators such as energy density, fast-charging capability, and cycle life, emerging as a core driver for the LIB industry's transition from "scale expansion" to "quality-driven development."

I. Core Applications of Lithium-Ion Dry Process Technology: Reconstructing Electrode Manufacturing Logic

The core innovation of dry process technology lies in abandoning the wet process's dependence on toxic organic solvents, instead adopting a technical route of "dry mixing - precise forming - in-situ composite" for electrode preparation. Its application scenarios now cover power LIBs, energy storage LIBs, and other core areas, evolving into three mainstream process directions:

1. Dry Calendering Process: The Mainstream Choice for Power Batteries

This process uses high-speed shearing to mix positive and negative active materials with conductive agents and dry binders into uniform dry powder, which is then directly pressed onto current collectors via high-precision calendering equipment to form a dense yet porous electrode layer. Currently widely applied in power batteries for new energy vehicles, especially lithium iron phosphate (LFP) systems, leading domestic battery manufacturers have achieved large-scale mass production, adapting to various models including passenger cars and commercial vehicles.

2. Electrospinning Dry Process: A Breakthrough Path for High-Energy-Density Batteries

Targeting high-performance materials such as high-nickel ternary cathodes and silicon-based anodes, the electrospinning dry process uses a high-voltage electric field to convert a mixed melt of polymers and active materials into nanofibers, which are directly deposited on current collectors to form self-supporting electrodes. These electrodes meet mechanical strength requirements without additional calendering, and the three-dimensional porous structure formed by interwoven nanofibers provides sufficient buffer space for high-active materials with high volume expansion rates. This process is currently undergoing pilot applications in high-end power batteries and special energy storage batteries.

3. Dry Coating Process: A Cost-Optimized Solution for Energy Storage Batteries

Addressing the cost sensitivity of large-scale energy storage scenarios, the dry coating process simplifies dry powder mixing and calendering steps. It uses electrostatic adsorption to uniformly coat dry active material powder onto current collectors, followed by low-temperature curing to form electrodes. This process significantly reduces equipment investment and production cycles, and has been mass-produced in large-capacity energy storage LIBs, becoming a key technology for reducing costs and improving efficiency in energy storage stations.

II. Core Performance Improvements: Significant Breakthroughs in Four Dimensions

The performance enhancement brought by dry process technology is not marginal optimization but a leap forward in core indicators through the reconstruction of electrode microstructures, with specific manifestations as follows:

1. Fast-Charging Capability: Achieving Breakthroughs in Rapid Energy Supplement

Wet electrodes are prone to micropore collapse during solvent drying, resulting in tortuous lithium-ion migration paths and limited fast-charging efficiency. In contrast, dry electrodes enable precise control of porosity, forming well-connected three-dimensional ionic channels that greatly enhance lithium-ion migration rates, making fast charging a reality. Both LFP and ternary dry-process power batteries achieve much faster charging speeds than their wet-process counterparts. Particularly suitable for new energy commercial vehicles, this technology significantly shortens charging time, approaching the refueling experience of fuel-powered vehicles.

2. Energy Density: Effectively Enhancing Unit Capacity

The dry process avoids the problem of active material encapsulation by binders in the wet process, allowing more active materials to participate in electrochemical reactions. Meanwhile, the dense electrode layer formed by calendering can accommodate a higher loading of active materials. This advantage is reflected in both conventional and high-performance battery materials: it not only improves the energy density of traditional LIB systems to support long-range vehicle requirements but also adapts to next-generation materials such as silicon-based anodes, driving energy density to new heights.

3. Cycle Life: Greatly Extending Service Period

Residual solvents in wet electrodes decompose to produce gas during cycling, leading to electrode detachment, battery swelling, and reduced lifespan. Dry electrodes completely eliminate solvent residues, and the interface bonding strength between active materials and current collectors is higher, resulting in stronger structural stability. Whether in energy storage or commercial vehicle power scenarios, dry-process LIBs can withstand more charge-discharge cycles, with a significantly longer service life than wet-process batteries, reducing the total cost of ownership.

4. Safety Performance: Significantly Reducing Risk Hazards

The dense structure and stable interface bonding of dry electrodes make them more reliable under extreme conditions. In safety tests such as needle penetration and extrusion, dry-process batteries have a lower risk of thermal runaway without fire or explosion. Additionally, dry-process batteries maintain higher capacity retention rates in both high and low-temperature environments, with a wider operating range, meeting safety requirements across various application scenarios.

III. Core Differences from the Wet Process: The Underlying Logic of Performance Improvement

The performance advantages of dry process technology stem from the reconstruction of the underlying logic of electrode manufacturing. Its core differences from the wet process directly determine performance ceilings:

The wet process relies on natural forming after solvent evaporation, making electrode microstructures difficult to control and prone to issues such as micropore collapse, active material encapsulation, and weak interface bonding—problems that not only affect performance but also lead to higher production energy consumption. In contrast, the dry process precisely constructs electrode structures through mechanical force and electric field action, achieving "structure-on-demand design": electrode porosity can be flexibly adjusted, active materials can fully exert their effects, and interface bonding is tighter. At the same time, it eliminates high-energy-consuming steps such as high-temperature drying, avoiding material thermal degradation and enabling green production.

This difference is essentially a distinction between "passive forming" and "active design," which is the core reason why dry process technology can continuously break through the performance ceiling of lithium-ion batteries.

IV. Industry Impact and Future Trends

The large-scale application of dry process technology not only pushes LIB performance to new heights but also reshapes the industry's competitive landscape: in the power sector, dry-process power batteries have become a core configuration for new energy commercial vehicles and high-end passenger cars, driving the construction of fast-charging networks into a new phase; in the energy storage sector, dry-process energy storage batteries, with their advantages in cost and lifespan, are accelerating the industry's transition from "policy-driven" to "market-driven."

In the future, dry process technology will continue to evolve in multiple directions: first, expanding multi-material compatibility to adapt to next-generation battery materials such as high-nickel ternary cathodes, silicon-based anodes, and manganese-rich cathodes; second, advancing process integration to achieve "electrode - cell - module" integrated manufacturing, further reducing production costs; third, pursuing performance optimization, continuously breaking through the limits of energy density, fast-charging speed, and cycle life through technical upgrades.

From process innovation to performance leap, dry process technology for lithium-ion batteries not only addresses the inherent bottlenecks of the wet process but also defines the performance standards for next-generation LIBs. As equipment maturity improves and raw material costs decrease, dry process technology will gradually replace the wet process as the mainstream, injecting sustained growth momentum into new energy vehicles, energy storage, smart grids, and other fields, and accelerating the global achievement of "dual carbon" goals.