Supercapacitors – a modern method of storing electrical energy

Uneven energy production, depending on changing demand, is one of the main challenges facing the modern energy sector at both local and national levels. To address this issue, various solutions are being implemented to stabilise power grids and maximise the use of energy from renewable sources. One such solution is electricity storage. In recent years, this technology has been developing very rapidly, and supercapacitors may play an increasingly important role in the future.

Electricity storage

Energy production is fluctuating. This means that it cannot be used exclusively for the current power supply needs of devices. One way to deal with this situation is to feed surplus energy into the grid. An electrical cable line receives and transmits energy from the GPO and then feeds it into the electricity distribution system. However, there are other solutions that allow energy production and consumption to be managed without the need to connect to the grid. One of them is electricity storage.

Storing electricity (for later use) allows surplus energy to be used efficiently, while bringing a number of benefits, such as greater energy security and independence, financial savings, a positive impact on the environment, and voltage stabilisation in the power grid.

Modern methods of energy storage

Batteries are a traditional solution used in the energy storage process, with lithium-ion (Li-ion) batteries remaining the most popular. They offer many advantages, such as high efficiency and high energy density. Unfortunately, they also have significant disadvantages, including gradual cell degradation and problems related to their subsequent storage. For this reason, new energy storage technologies are constantly being developed to reduce the shortcomings of existing solutions. One of them is supercapacitors.

Supercapacitors are electrolytic capacitors with a capacity that significantly exceeds that of traditional capacitors. They are distinguished by, among other things, high durability, very high efficiency and lightning-fast charging and discharging times. Unlike lithium-ion batteries, they do not use chemical reactions to release energy, but store electrical charge in a double electric layer called the Helmholtz double layer. In addition, supercapacitors can operate in a wider range of ambient temperatures than traditional batteries.

Application and future of supercapacitors

The disadvantages of supercapacitors include low energy density, i.e. a small amount of stored energy per unit of device mass. For this reason, supercapacitors are often used to supplement other solutions, creating hybrid energy systems. In such technologies, battery cells are responsible for supplying energy during normal operation of the device, while supercapacitors are used in situations of sudden, rapid increases in power demand.

However, observing the development of energy storage technology, it can be assumed that supercapacitors may represent the future of energy storage. Scientists around the world recognise their potential and are conducting intensive research into the development of this technology. Among the solutions developed, graphene supercapacitors stand out in particular. Graphene increases their energy density, thereby reducing one of the main drawbacks of traditional supercapacitors, namely low energy density. As a result, the supercapacitors of the future will be lighter and more compact, which in turn increases the chances of large-scale industrial and commercial implementation of this solution.