Cement, kolsvart, elektrolyter och vatten utgör ett enkelt recept för en mångsidig ny superkondensator

If recent developments involving material science pan out, our world will look like a much different place in only a few years.  Over the past week, there is not only a lengthening list of scientists attempting to recreate and prove the validity of recent claims surrounding a potential room-temperature, ambient-pressure superconductor being called ‘LK-99’, but the Massachusetts Institute of Technology (MIT) also announced an intressant upptäckt of its own.  This would be a cost-effective supercapacitor made from non-exotic materials.

Vad är en kondensator?

Capacitors are devices that store electrical energy by accumulating an internal imbalance of electric charge across two conductive plates separated by an insulator or dielectric.

Vad gör en ‘Super’?

• Lagringskapacitet: Supercapacitors can store a much larger amount of electrical charge compared to standard capacitors. This is due to the high surface area of the electrodes and the very thin distance between them, which allows for more charge to be stored.
• Energitäthet och effekt‑densitet: While capacitors generally have a higher power density (they can deliver energy quickly) but lower energy density (they store less energy), supercapacitors bridge the gap between capacitors and batteries by having both high power density and a relatively high energy density.
• Konstruktion: Supercapacitors often use different materials and construction methods. They typically utilize porous carbon materials for the electrodes, which provide a large surface area, and an electrolyte that allows for the movement of ions. The large surface area and special construction enable the supercapacitor to store more energy.
• Laddnings- och urladdningshastigheter: Supercapacitors can be charged and discharged much more rapidly than batteries, and they can endure many more charge and discharge cycles than batteries without significant degradation. While standard capacitors also charge and discharge quickly, supercapacitors can hold the charge longer due to their larger storage capacity.

Simply put, while standard capacitors and supercapacitors operate on the same basic principle of storing energy in an electric field, supercapacitors are distinguished by their much higher storage capacity, different construction materials, and their ability to combine the characteristics of both capacitors and batteries.

Var används superkondensatorer?

So now that you know what a supercapacitor is, where are they useful?  Supercapacitors are commonly used in applications where quick energy delivery and efficient storage are essential. Here are some of the typical areas where you might find supercapacitors:

• Elfordon (EV): Supercapacitors can provide the rapid bursts of power required for acceleration and can also capture energy during regenerative braking, improving the overall efficiency of the vehicle.
• Kollektivtrafik: In buses and trams, supercapacitors can be used to store energy quickly during brief stops and then provide the energy needed for acceleration, reducing the strain on the main power source.
• Förnybara energisystem: Supercapacitors can store energy from renewable sources like solar and wind, releasing it when needed. This helps in smoothing out fluctuations in energy supply when the sun and wind are in short supply.
• Avbrottsfri strömförsörjning (UPS): In systems that require a continuous power supply, supercapacitors can provide temporary power during short outages or until backup generators come online.
• Konsumentelektronik: In some devices, supercapacitors can provide the quick bursts of energy required for certain functions, such as flash photography in cameras and high-end car audio installations.
• Medicintekniska apparater: Supercapacitors can be used in medical devices like defibrillators which require reliable and instant power delivery.
• Industriell utrustning: In industrial settings, supercapacitors can provide the high power needed for short durations in various machinery and tools.
• Nätstabilisering: Supercapacitors can be used in the electrical grid to provide rapid response to changes in demand or supply, helping to stabilize the grid and prevent fluctuations.
• Trådlösa kommunikationsenheter: They can be used to provide the energy needed for transmitting signals, especially in remote or hard-to-reach locations where battery replacement is challenging.
• Smart grid- och mikronätstillämpningar: Supercapacitors can be part of intelligent energy management systems, helping to balance loads and store energy locally for more efficient use.
• Luft- och rymd samt försvar: In aerospace applications, supercapacitors can provide reliable power for critical systems that require high reliability and performance.

Overall, the versatility, high power density, and rapid charge/discharge capabilities of supercapacitors make them suitable for a wide range of applications where both energy storage and quick energy release are required. As you can see from the above list, supercapacitors are already in use in a plethora of industries.  As such, the recent discovery made by MIT is particularly intriguing due to its potential to advance so many different implementations.

Ett nytt recept

Per MIT, the researchers involved with this discovery developed the method to produce a cement-based material with a high internal surface area by introducing carbon black into a concrete mixture. The resulting material, when soaked in a standard electrolyte like potassium chloride, forms a powerful supercapacitor. Notably, the amount of carbon needed is minimal, which makes the process both inexpensive and easily reproducible.

When creating a supercapacitor, it is important to remember that its performance is largely based on the internal surface area of its conductive plates.  MIT states that,

“The key to the new supercapacitors developed by this team comes from a method of producing a cement-based material with an extremely high internal surface area due to a dense, interconnected network of conductive material within its bulk volume.”

What is key to this discovery though, is that it was achieved with such mundane materials, found cheaply around the world – making it an extremely accessible technology.

Where this discovery gets interesting is when thinking of its potential future applications in stabilizing energy grids and demands.  The team describes one implementation in which the foundation of a home is made of the material.  Not only can the material be made just as robust as normal cement, the foundation of a home would have the capacitance to provide an entire day’s worth of electricity.   This could be drawn upon in power outages, during peak-rate hours, or other similar circumstances.

It is also useful for homes that leverage renewable energy, where supply is not constant.  During periods of excess creation, the energy stored in the foundation could be topped-up, while in periods of energy drought, it could be drawn upon.  Other implementations include wireless charging technology, serving communities and homes disconnected from traditional power grids, and more.

Avslutande ord

The importance of a cement-based supercapacitor is huge, given humans’ proclivity for building with the material.  Overall, the team believes that its,

“…material design of porous carbon-cement composites provides a scalable material solution for energy storage to support the urgent transition from fossil fuels to renewable energies.”

Not only would it be easily accessible, it could see fairly easy implementation in both small and large-scale projects.