The Berkeley Lab has created a conductive polymer coating known as HOS-PFM that could be used for coating lithium-ion batteries for electric vehicles (EVs). This could increase the range and life of EV batteries.
“The advance opens up a new approach to developing EV batteries that are more affordable and easy to manufacture,” said Gao Liu, a senior scientist in Berkeley Lab’s Energy Technologies Area.
How Does The HOS-PFM Coating Work?
The HOS-PFM coating ensures battery stability and rapid charge/discharge rates while extending battery life by simultaneously conducting electrons and ions. According to Liu, the coating also shows potential as a battery adhesive that might increase a lithium-ion battery’s typical lifespan from 10 to roughly 15 years.
Liu and his team coated aluminium and silicon electrodes with HOS-PFM and studied the performance of the electrodes in a lithium-ion battery setup to show the material’s excellent conductivity and adhesive capabilities.
Due to their potential for having large amounts of energy stored in them and their lightweight profiles, silicon and aluminium are viable electrode materials for lithium-ion batteries. However, after numerous charge/discharge cycles, these inexpensive and abundantly available materials quickly degrade and that is the main drawback of these materials.
According to Liu, the HOS-PFM coating could enable the use of electrodes in lithium-ion batteries that contain up to 80% silicon, boosting their energy density by at least 30%. And because silicon is less expensive than graphite, which is now the industry standard for electrode materials, more entry-level EVs may be available due to cheaper batteries and the team will collaborate with companies to scale up HOS-PFM for mass production.
Now we know the recent developments in the coating of EV batteries, let us look into the basics.
How Are Lithium Batteries Insulated?
EV lithium batteries generate a lot of heat while charging or operating. Insulation is required automatically to support the maintenance of a thermal balance for these batteries. The four primary lithium battery heat management strategies are as follows,
- Air cooling
- Boiling
- Liquid cooling
- Phase Change Materials (PCM)
Why Do EV Batteries Need To Be Coated?
High-voltage batteries within the EV, which call for top-notch EV battery insulation, store the necessary energy.
Finding the optimum materials is, therefore, necessary to ensure that EV lithium-ion batteries have the ideal insulation. Since it offers 100% protection from electrical discharges, using the best insulating material in the form of foam, liquid, or film is a safety precaution for drivers and vehicles.
Here are a few factors to be considered while selecting an ideal coating for EV batteries.
Factors To Be Considered While Selecting The Coating
#1. Thickness (Ratio of Thickness to Efficiency)
In order to achieve the ideal balance between the battery’s compactness and the energy density the film can hold, the thickness of the film is a key factor for battery makers when it comes to electrical insulation.
#2. Resilience
Extreme temperatures and outside pressure should not harm the thermally conductive materials. Can it withstand the physical strain the batteries will put on it?
#3. Cost to Operate Ratio
Electric insulators come in a variety of strengths and costs, with the most powerful ones costing more. To draw potential purchasers, EVs and their internal parts should continue to be reasonably priced. Nevertheless, there should be a sensible balance between effectiveness and expense.
#4. Electrical Resistance
To satisfy stringent electrical barrier and insulation standards, the material must exhibit the dielectric strength required.
#5. Component Weight
Another crucial element is the weight of the materials. The more weight the insulating material adds to the vehicle, the less it can perform to its full capability.
#6. Resistance to Vibration
Due to the functioning of the vehicle, the lithium batteries and EV battery insulators will be subjected to noise and vibration levels continuously. As a result, the material must be easily able to endure certain physical pressure.
#7. Resistance to Chemicals
Given that it will probably be exposed to chemicals while operating the vehicle, the coating material’s behaviour when exposed to chemicals is crucial.
The newly developed HOS-PFM coating satisfies all of the criteria for a good coating material thus it could bring a lot of changes in the upcoming EVs.
