From Wet to Dry: The Transformation Logic of the Lithium - Ion Battery Industry in Processes, Electrode Sheets, and Forming Links

The technological iteration of the lithium - ion battery industry has always centered around the three core propositions of "efficiency, cost, and safety". The transformation from the wet process to the dry process is not a technical adjustment in a single link but a systematic change that runs through the entire process from electrode sheet preparation to battery forming. This change shows unique advantages in simplifying processes, utilizing materials, optimizing performance, etc., and is reshaping the underlying logic of lithium - ion battery production.

Dry Process: Reconstructing the Efficiency and Environmental Protection Boundaries of Electrode Sheet Preparation

In the electrode sheet production link, the wet process has long relied on the complex flow of "solvent dispersion - coating - drying - solvent recovery": active materials, conductive agents, and binders are dispersed in organic solvents such as NMP to form a slurry, which is coated on the current collector. Then, high - temperature drying is needed to remove the solvent, and at the same time, the volatile solvent is treated through a recovery system. This process not only has high energy consumption (the energy consumption of the drying link accounts for more than 40% of the total energy consumption in electrode sheet production) but also has the risk that solvent residues affect electrode performance. Moreover, the maintenance cost of recovery equipment continues to erode corporate profits.

The dry process has completely subverted this model. Taking the "dry electrode" technology as an example, it uniformly blends active materials with solid binders through mechanical mixing, and then directly presses the mixture onto the current collector by physical means such as rolling, without the participation of solvents throughout the process. This process eliminates links such as solvent procurement, slurry stirring, and high - temperature drying, shortening the electrode sheet production process by more than 60% and reducing energy consumption by more than 50%. Pilot data from a power battery enterprise shows that after adopting the dry electrode process, the floor area of a single production line is reduced by 30%, production efficiency is increased by 40%, and the safety level requirements of the workshop are significantly reduced because there is no need to handle solvents.

More importantly, the dry process has stronger compatibility with materials. In the traditional wet process, the chemical properties of solvents will limit the selection of active materials (for example, some high - capacity silicon - based materials are prone to react with solvents). However, the physical mixing method of the dry process can be adapted to more new materials, providing more space for the research and development of high - energy density electrodes. For example, the utilization rate of active materials in silicon - carbon composite electrodes prepared by the dry process is 15% higher than that in the wet process, and the problem of electrode cracking caused by the expansion of silicon materials is avoided.

Forming Link: Adaptability and Performance Gains of the Dry Process

The battery forming link (such as cell packaging and assembly) has strict requirements on the physical properties of electrode sheets, and the electrode sheets prepared by the dry process show unique advantages here. Due to high - temperature drying, wet electrode sheets are prone to problems such as edge curling and uneven thickness. In the lamination or winding process, additional calibration procedures are required; otherwise, the alignment deviation inside the cell will be caused, affecting the cycle life. Dry electrode sheets are formed by rolling, and the thickness consistency error can be controlled within ±1μm, and the edge flatness is improved by 50%, which significantly reduces the rejection rate in the forming process.

In addition, the integration of the dry process simplifies the forming process. In traditional wet production, the preparation of electrode sheets and diaphragms is an independent link, and parameters need to be controlled separately to ensure matching. However, some dry processes can realize the "electrode - diaphragm integration" production, directly combining the electrode layer and the diaphragm layer through co - extrusion or composite forming technology, reducing the alignment steps during cell assembly, and further accelerating the production rhythm. This integrated structure can also reduce the interface contact resistance inside the cell and increase the energy density by about 5%.

Transformation Value from a Full - Chain Perspective

From the full process of electrode sheets to forming, the transformation value of the dry process is reflected in the synergistic effect of "cost reduction, efficiency improvement, and quality enhancement". On the cost side, the dry process saves costs such as solvents, energy consumption, and equipment maintenance, which can reduce the comprehensive cost of batteries by 15% - 20%. In fields sensitive to costs such as energy storage batteries, this advantage directly determines product competitiveness. On the efficiency side, the simplification of the process accelerates the production capacity climbing speed of factories, making them more able to adapt to rapid market fluctuations. On the performance side, electrodes and diaphragms with no solvent residues and more stable structures provide a basic guarantee for the long cycle and high safety of batteries.