The demands on small devices such as medical sensors, smartwatches and other Internet of Things tools are high. For instance, the devices must work for as long as possible, provide high performance and be able to be charged within seconds. A new type of water-based battery offers a solution.
The battery was developed by researchers at TU Delft and the National University of Singapore. It involves so-called pseudocondensators. This is a type of electrochemical capacitors that store energy via faradaic reactions. These are redox reactions at the electrode surface. Pseudocondensators offer important advantages. For instance, the capacitors can store a large amount of energy in a limited space. They can also be charged directly.
Trade-off between power and energy
The battery technology we have so far requires a trade-off between power and energy. For instance, you can design a battery to store more energy, but that then means it can deliver energy more slowly. At the same time, you can design a capacitor that can deliver high power in a short time, but it can store less energy as a result.
The new battery developed by researchers at TU Delft and the National University of Singapore offers a solution. The battery combines high and fast energy storage with fast energy release. The technology is made of modified polymers and 2D materials.
Various benefits
According to the researchers, the technology offers several advantages. For instance, the battery is pliable, with bending not leading to loss of performance. Among other things, this allows the battery to be integrated into small applications in new ways. In addition, the material has high stability and does not deteriorate, even after 100,000 charges.
Another key advantage pointed out by the researchers is size flexibility. For instance, the design is scalable, and can therefore be used for electric vehicles (EVs). "For example, the capacitor could allow cars to start faster or buses on capacitor power could require less frequent charging," the researchers report.
Non-flammable
The researchers also point to safety. For instance, the battery uses an aqueous electrolyte, which is therefore non-flammable. This is a big advantage, as battery fires are notoriously difficult to burn. The fire brigade in the Netherlands, for instance, uses containers of water into which an EV that has caught fire can be hoisted, with the aim of preventing the battery from reigniting.
Finally, the battery is environmentally friendly and easily recyclable. For instance, the pseudocondensators are water-soluble, so they can be easily recycled and regenerated after disassembly from a device.
More information about the new battery can be found in an article in Nature Communications, where the researchers share more details about their findings.
