From Wet to Dry: The Inevitable Path for the Lithium-Ion Battery Industry

Against the backdrop of the global energy transition, lithium-ion batteries, as the core carrier of the new energy revolution, have always seen their production process iterations revolve around three core goals: "cost reduction, efficiency improvement, and environmental protection." For a long time, wet processes have dominated due to their mature technical systems. However, as the industry pursues green manufacturing, cost control, and new battery structures, dry processes are upgrading from an "alternative option" to a "strategic direction." The shift from wet to dry is not just a switch in technical routes but an inevitable choice for the lithium-ion battery industry to meet future challenges.

I. Driven by Environmental Pressures: A Green Revolution to End "Solvent Dependence"

The "hidden pain" of wet processes emerges from the solvent link. Take the mainstream solvent NMP (N-methylpyrrolidone) as an example: each GWh of lithium-ion batteries produced consumes approximately 800 tons of NMP. Even with recovery systems, 5%-10% of the solvent is emitted as VOCs (volatile organic compounds). These emissions not only require costly environmental protection equipment (a solvent recovery system costs about 20 million yuan) but also directly conflict with "dual-carbon" policies and global environmental regulations. The EU Battery Regulation explicitly requires a 30% reduction in the full-life-cycle carbon emissions of power batteries by 2030, and solvent volatilization and drying energy consumption (accounting for 30% of total energy consumption) in wet processes have become the biggest obstacles.

Dry processes solve this problem at the source: no liquid solvents are used throughout, avoiding the transportation and storage risks of hazardous substances like NMP, and completely eliminating VOC emissions. Environmental protection investments can be reduced by over 60%. Under the hard constraints of "dual-carbon" goals, the "zero-pollution" attribute of dry processes has become a "passport" for leading enterprises to obtain policy support and enter high-end markets such as the EU.

II. Escalating Cost Competition: The Tipping Point from "Scale-Driven Cost Reduction" to "Process-Driven Cost Reduction"

Cost competition in the lithium-ion battery industry has long entered an era of "competing for every tiny margin." Although wet processes have reduced unit costs to a relatively low level through large-scale production, the "cost ceiling" of inherent processes is becoming increasingly obvious: solvent procurement (NMP costs about 20,000 yuan/ton), energy consumption of drying equipment (annual electricity costs for a single GWh exceed 10 million yuan), and maintenance of solvent recovery systems, among others, collectively account for 15%-20% of battery production costs.

The cost reduction logic of dry processes is more direct: eliminating solvents and recovery systems reduces raw material costs by 8%-10%; removing the drying link cuts energy consumption by over 30%; shorter processes compress production cycles from 48 hours (wet) to less than 24 hours, increasing equipment utilization by 50% and reducing factory space requirements for a single GWh by 30%. Industry estimates show that once dry processes mature, the unit cost of power batteries can drop below 0.5 yuan/Wh, 0.1-0.15 yuan/Wh lower than wet processes. This means that for an electric vehicle equipped with a 70kWh battery, battery costs alone can be reduced by 7,000-10,500 yuan, sufficient to meet automakers' profit demands for "affordable electric vehicles."

III. Driven by Technological Iteration: A "Compatibility Revolution" for New Battery Types

With the application of new materials such as high-nickel ternary materials, silicon-based anodes, and solid electrolytes, the "compatibility bottlenecks" of wet processes are gradually exposed. For example, silicon-based anodes undergo 300% volume expansion during charge-discharge, and the PVDF binder used in wet processes easily reacts with the silicon surface in solvents, leading to electrode cracking. High-nickel cathodes (e.g., NCM811) are sensitive to moisture; trace water residues in wet solvents may cause material deterioration, affecting battery safety.

Dry processes achieve material bonding through the principle of "mechanochemistry," with no solvent involvement, perfectly avoiding these issues: dry binders (such as PTFE) form molecular-level bonding with active materials through mechanical shearing, increasing tolerance to volume expansion of silicon-based anodes by more than 3 times. Meanwhile, the dry environment ensures "zero moisture contact" for high-nickel materials, extending cycle life by 20%. More critically, the porous structure of dry electrodes (10%-15% higher porosity than wet electrodes) provides channels for rapid lithium-ion migration, adapting to 800V high-voltage platforms and fast charging above 4C—exactly the core technical support for new energy vehicles to shift from the "range race" to the "fast-charging race."

IV. Reshaping the Industrial Landscape: A Window of Opportunity from "Following Maturity" to "Defining Standards"

After decades of development, wet processes have highly unified industry standards for equipment, materials, and parameters, making it difficult for latecomer enterprises to break through technical barriers.

For instance, the special requirements of dry processes for binders (needing room-temperature self-adhesion) may drive innovation in PTFE alternatives; the precision design of dry mixing equipment (such as shear strength control in twin-screw mixers) may restructure the equipment supply chain. Whoever first overcomes the stability challenges of dry processes (e.g., electrode uniformity control) will gain   in next-generation battery manufacturing—which is the underlying logic for leading enterprises to accelerate their   in dry processes.

The shift from wet to dry is not a negation of mature technologies but an inevitable choice at a specific stage of industrial development. Wet processes will remain dominant in high energy density and high consistency fields for a long time, while dry processes have opened up new tracks in environmental protection, cost, and fast charging. Future lithium-ion battery factories may present a synergistic pattern of "wet processes for high-end products, dry processes for mass-market products." What is certain is that whoever masters dry processes earlier will seize the initiative in the next round of competition in the new energy industry.