Scientists in China have found that the “phase inversion” method could improve the comprehensive performance of the porous electrodes, making them a more viable tool for developing advanced energy storage devices.
Hongzhang Zhang and his team from Dalian Institute of Chemical and Physics designed the “phase inversion” method, a universal method to create high-performance porous electrodes for nanoparticle-based energy storage devices. They achieved excellent cohesive strength and electron/ion transport rates by simply immersing aluminum foil coated with electrode slurry (solvent, binder, carbon and active materials) into a coagulation bath of non-toxic solvents such as water and alcohol.
“Portable electronic devices and electric vehicles need energy storage devices with high energy density”, says Zhang, who adds that electrodes with high loading of active materials and excellent electrochemical performance is the key to solve this problem. However, the electrodes prepared via traditional method (directly drying the slurry on the current collector) cannot meet this requirement, and thus hinder the development of Li-ions batteries, Li-O2 batteries, Li-S batteries and super capacitors. Hence, finding a method to solve the above issues is of great significance.
The as proposed “phase inversion” method could form the “tri-continuous” structure, which is constructed with the binder networks, electron paths and ion channels separately interconnected. It perfectly solved the above issues by simultaneously providing excellent bindering strength, e– conductivity and Li+ conductivity. Equally important, this method is environmental friendly and energy-saving, by replacing the toxic and hardly volatile NMP solvents with water (or other solvents) in the electrode manufacture process.
This method is not complicated, and is universally adaptable for preparing high performance porous electrodes, thus has a great potential to reform the future manufacture process of electrodes.
The PIE formation mechanism and internal ion/electron transport. a) Ternary phase diagram of instantaneous phase inversion. b) Schematic illustration of the prepared PIE. c) Enlarged view of (b) and internal ion/electron transport.
