Lithium iron phosphate-coated aluminum foil.
The main production process of carbon-coated aluminum foil.
Brushing——the aluminum foil is continuously and uniformly passed through the brushing carbon coating box filled with nitrogen gas, in the brushing carbon coating box with nitrogen gas airflow carrying aluminum powder particles sprayed onto the surface of the aluminum foil, rubbing the surface of the aluminum foil to bristle and remove the surface aluminum oxide layer, after brushing the aluminum foil using nitrogen gas airflow to remove the surface aluminum powder particles.
Carbon coating——in which the carbon conductive paste is applied to the surface of the aluminum foil after grossing and blowing clean in a grossing and carbon coating box.
Heating and drying——the aluminum foil coated with carbon conductive paste is passed into the heating and drying box, and heated clean air is injected into the heating and drying box to dry the carbon conductive paste.
Carbon coated aluminum foil is a breakthrough technological innovation in the surface treatment of battery conductive substrates using functional coatings.
Carbon coated aluminum foil/copper foil is a well-dispersed nano conductive graphite and carbon-coated particles, uniformly and delicately coated on aluminum foil/copper foil.
The carbon-coated aluminum foil provides excellent static conductivity and collects micro-currents from the active material, which can significantly reduce the contact resistance between the positive/negative materials and the current collection, and can improve the adhesion ability between them, which can reduce the amount of binder used, thus producing a significant improvement in the overall performance of the battery.
Advantages of carbon-coated aluminum foil in lithium battery applications.
- Inhibiting cell polarization, reducing thermal effects, and improving multiplier performance.
- Reduced cell internal resistance and significantly reduced dynamic internal resistance increase during cycling.
- Improving consistency and increasing the cycle life of the cell.
- Improving the adhesion of the active material to the collector fluid and reducing the cost of pole piece manufacturing.
- protecting the collector fluid from corrosion by the electrolyte.
- Improving the processing performance of lithium iron phosphate and lithium titanate materials.
The difference between carbon coated aluminum foil and bare aluminum foil for lithium battery applications.
The electrochemical impedance spectra of batteries made of carbon-coated aluminum foil and photo aluminum foil are significantly different.
The carbon-coated aluminum foil has a significant improvement on the internal resistance of the battery, while the impedance spectrum of batteries made of photo aluminum foil has an additional segment of capacitive resistance arc generated by the double layer capacitance at the gap between the aluminum foil and the active material interface.
The storage test results show that the use of carbon-coated aluminum foil results in less self-discharge and improved storage performance.
The multiplier charge/discharge test results show that the constant current charge ratio and the median discharge voltage of the carbon-coated aluminum foil battery are higher during high current charge/discharge, and the battery has less polarization and better power performance. The low-temperature performance of carbon-coated aluminum foil batteries is also more competitive, with a higher initial discharge voltage plateau and higher discharge capacity. The carbon-coated aluminum foil also significantly improves the 1 C cycle and 3 C cycle performance of the battery.
Meanwhile, it was found that different types of coated carbon layers have different performance enhancement effects on LiFePO4 batteries: coated graphene aluminum foil has better performance enhancement on LiFePO4 batteries under high power conditions than coated carbon black aluminum foil because the graphene sheet layer has better improvement on electrical and thermal conductivity than carbon black coating in the direction along the aluminum foil surface.