In modern Formula 1 cars, the Energy Store (ES) plays a pivotal role in the hybrid power unit system, serving as the battery pack that stores electrical energy recovered from the car’s Energy Recovery Systems (ERS), which include the MGU-K (Motor Generator Unit - Kinetic) and MGU-H (Motor Generator Unit - Heat). The ES is responsible for storing energy captured from braking (via the MGU-K) and from the turbocharger (via the MGU-H), and then deploying this stored energy to boost the car’s performance, delivering additional power to the drivetrain when needed.
The Energy Store is essentially a high-performance lithium-ion battery pack designed to store and release electrical energy with maximum efficiency. Operating in an extreme environment, the ES must withstand high temperatures, mechanical stress, vibrations, and exposure to chemicals and other harsh conditions. To meet these demands, polymers are extensively used in the construction and protection of the ES. Polymers are chosen not only for their lightweight properties and thermal resistance, but also for their non-corrosive and non-conductive nature, which are essential for ensuring the safety, durability, and efficiency of the system.
The Role of the Energy Store in Formula 1
The Energy Store is central to the functioning of the hybrid power unit in F1 cars. It works by capturing and storing energy from two key sources:
- Braking (MGU-K): When the car brakes, the MGU-K captures kinetic energy that would otherwise be lost as heat. This energy is converted into electrical power and sent to the Energy Store.
- Turbocharger Heat (MGU-H): The MGU-H recovers energy from the exhaust gases that drive the turbocharger. This energy is also converted into electrical power and stored in the ES.
Once the energy is stored in the ES, it can be deployed to provide additional power to the car, such as during acceleration or to aid overtaking. The ES enables the car to operate more efficiently, reducing fuel consumption while delivering a performance boost when necessary.
Why Polymers Are Extensively Used in the Energy Store
The ES operates in a challenging environment where it is exposed to high heat, electrical currents, vibrations, and corrosive elements such as fuels, oils, and coolants. Polymers are ideal materials for various components of the Energy Store because they offer several key benefits:
1. Non-Corrosive Properties
One of the major reasons polymers are extensively used in the Energy Store is their inherent resistance to corrosion. The ES is often exposed to chemicals, such as fuel, hydraulic fluids, and coolant, which can cause metal components to corrode over time. Corrosion can degrade the performance and safety of the battery system, leading to failures or inefficiencies.
- Polymers such as PTFE (Polytetrafluoroethylene) and PEEK (Polyether Ether Ketone) are naturally resistant to chemical corrosion, making them ideal for use in battery casings, seals, and protective coatings. These materials ensure that the Energy Store remains intact and operational even after prolonged exposure to harsh chemicals and extreme environments. By preventing corrosion, polymers help extend the life of the ES and reduce the need for frequent maintenance or replacements.
2. Non-Conductive Nature
Polymers are excellent electrical insulators, meaning they do not conduct electricity. In the Energy Store, where high-voltage electrical currents are generated, stored, and transmitted, it is essential to use materials that prevent electrical short circuits and ensure that the electrical energy remains safely contained.
-
Polyimide films such as Kapton are used for insulating battery cells and wiring within the ES. These films offer high dielectric strength, ensuring that electrical currents are safely isolated within the system. This prevents energy from escaping unintentionally and minimises the risk of electrical malfunctions or short circuits.
-
PTFE is also widely used in the ES as an insulator for wiring and connectors. Its non-conductive nature ensures that the electrical components in the ES are protected from the high voltages generated by the energy recovery systems, safeguarding the integrity of the electrical circuitry.
By using non-conductive polymers, Formula 1 teams can ensure that the Energy Store operates safely and efficiently, preventing electrical faults that could compromise performance or endanger safety.
3. Thermal Resistance
During energy recovery and deployment, the ES generates significant amounts of heat, and the battery cells need to be kept within a safe operating temperature range to maintain performance and avoid overheating. Polymers are ideal for thermal management because they can withstand high temperatures without degrading or losing their insulating properties.
- PEEK and PTFE are often used in insulating layers and heat shields within the Energy Store. These materials can endure high temperatures while providing effective insulation between battery cells, helping to prevent thermal runaway (a situation where excessive heat causes the battery cells to degrade or fail).
By maintaining the thermal stability of the ES, polymers help ensure that the energy storage and release processes occur efficiently, even under the extreme heat generated during racing.
4. Lightweight Construction
Reducing the overall weight of a Formula 1 car is crucial for improving performance, as a lighter car can accelerate faster and handle more effectively on the track. Polymers are significantly lighter than metals, making them ideal for use in the construction of the Energy Store’s housing and protective components.
- Carbon fibre-reinforced polymers (CFRP) are commonly used for the outer casing of the Energy Store, providing a strong yet lightweight protective shell for the battery cells. The use of CFRP reduces the weight of the ES, allowing the car to perform better without sacrificing strength or durability.
This weight reduction is critical in Formula 1, where every gram saved contributes to faster lap times and better fuel efficiency, giving teams a competitive edge.
5. Vibration Damping and Durability
The Energy Store is subjected to significant vibrations and shocks during a Formula 1 race, especially when the car is navigating high-speed corners, braking hard, or accelerating rapidly. Polymers help protect the battery pack from these mechanical stresses, ensuring the components remain intact and functional throughout the race.
- Elastomeric polymers such as silicone and EPDM (Ethylene Propylene Diene Monomer rubber) are used for vibration damping mounts and gaskets within the Energy Store. These materials absorb vibrations and provide flexibility, preventing damage to sensitive battery cells and electrical connections.
By reducing the impact of vibrations and shocks, elastomeric polymers help extend the lifespan of the Energy Store and improve its reliability during races.
Key Benefits of Using Polymers in the Energy Store
-
Corrosion Resistance: Polymers such as PTFE and PEEK prevent corrosion caused by exposure to chemicals and harsh environments, ensuring the longevity and reliability of the ES.
-
Electrical Insulation: The non-conductive properties of polymers like polyimide and PTFE protect the battery system from short circuits and electrical faults, ensuring safe energy storage and deployment.
-
Thermal Management: Polymers with high thermal resistance, such as PEEK, help manage the heat generated by the battery cells, preventing overheating and maintaining efficient operation.
-
Weight Reduction: CFRP and other lightweight polymers reduce the overall weight of the Energy Store, contributing to improved car performance and handling.
-
Vibration Damping: Elastomeric polymers provide flexibility and absorb vibrations, protecting the battery cells from damage and ensuring the durability of the Energy Store.
Conclusion
In Formula 1’s Energy Store, polymers are crucial for ensuring the system operates safely and efficiently in the demanding environment of a race car. Their non-corrosive and non-conductive properties, combined with their thermal resistance, lightweight construction, and vibration damping capabilities, make polymers the ideal material for various components within the ES. By using advanced polymers, F1 teams can optimise the performance, safety, and reliability of the Energy Store, allowing for efficient energy recovery and deployment, which is critical for the hybrid power unit’s success on the track.