The Japanese manufacturer Toray Engineering has developed an environmentally friendly coating system for secondary electrodes of lithium-ion batteries (LIB). It coats electrodes over base materials in the LIB electrode production process.
A new, highly efficient and proprietary drying system that recirculates and reuses hot air in the drying oven to reduce energy consumption in LIB electrode manufacturing compared to competitive systems can reduce energy consumption by about 25% compared to conventional machines.
In the production of LIB electrodes, a coating liquid is first applied to metallic base materials and dried. This liquid consists of a mixture of electrode materials and organic solvents. Although hot air drying is commonly used, whereby the LIB electrodes are dried with heated air, the inside of the oven must be kept at a constant high temperature in order to keep the concentration of the organic solvent in the oven below the prescribed explosion protection limits in a controlled manner, while at the same time outside air is drawn in for ventilation. As a result, energy consumption during electrode production accounts for around 45% of energy consumption in the entire LIB production process.
Optimized heat circulation
Toray's technology integrates the drying oven and the organic solvent collector into a single system to collect the solvent, circulate the heat and reuse it, although the hot air used in the drying oven has been passed through an off-gas treatment in a solvent collector outside the factory. This circuit makes it possible to minimize energy loss during solvent separation and avoid problematic phenomena.
In addition, since the system recirculates and reuses hot air, the air supply ducts for drawing in outside air and the exhaust ducts for discharging used air to the atmosphere and the exhaust gas treatment device can be simplified to reduce acquisition costs.
