Testing the adhesive strength of cathode & anode coatings
Application of the LUMiFrac® for testing the adhesive strength of cathode & anode coatings in lithium-ion batteries
In a lithium-ion battery, the smallest unit of each cell consists of two electrodes (anode and cathode), and the separator. The ion-conducting electrolyte is located in between. Typically, the main component of the anode is graphite, which is excellent for storing lithium ions during charging.
However, graphite’s limited electrical conductivity can cause inefficiencies in charge and discharge cycles. To boost the anode’s performance, the coating system is applied to a thin copper foil.
The copper foil enhances electrical conductivity which facilitates the electron flow between the anode and the rest of the battery, including the cathode. As a result, the battery’s internal resistance decreases, leading to more efficient charging and discharging processes. This translates to higher power output and better overall performance. The coating system prevents corrosion of the copper foil, ensures stability, and maintains electrolyte compatibility.
The active material of a cathode consists largely of a lithium transition metal oxide compound, like lithium cobalt oxide or lithium iron phosphate. While these materials have good energy storage capabilities, they can be chemically reactive and degrade over time.
To address this concern and improve stability and lifespan, the cathode coating system is applied to a thin aluminum foil. This foil and the corresponding coating system reduce or prevent undesirable side reactions and chemical degradation, ensuring the battery’s long-term stability and cycle life.
The coating process can be achieved using various techniques, such as solvent casting, extrusion coating, or lamination, depending on the specific requirements and manufacturing processes of the lithium-ion battery.
Overall, the coating system on the aluminum foil plays a vital role in ensuring the stability and safety of the cathode in a lithium-ion battery and preventing dendrite formation.
The adhesive strength of the coatings on the metal foils is one vital indicator for the overall performance of the lithium-ion battery.
The adhesion analyser LUMiFrac® is successfully utilized to determine the adhesive strength of coatings on copper foils for anodes and of aluminum foil coatings for cathodes in lithium-ion batteries.
A time saving of up to 80% can be achieved since, in contrast to other comparative methods, no clamping is required and up to 8 samples can be tested in parallel.
Learn more on 12 June.
