petrmalinak / Shutterstock
Last year witnessed a breakthrough in how we manage energy storage, which brought huge implications for the widespread adoption of renewable energy.
As our global resources of fossil fuels become depleted, and as the rate at which related harmful emissions enter our environment becomes critical, a world-wide shift has occurred where companies, consumers and governments are now focusing on how renewable, clean energy can replace fossil fuels. One of the major hurdles to overcome is dealing with renewable energy’s intermittent nature. Solar and wind sources, for example, only generate energy when the sun is shining, or when the wind is blowing, which isn’t for the entirety of the day. So, long-term storage options, such as supercapacitors and batteries, which can store surpluses of renewable energy to be used when input is low, have become increasingly important.
These storage devices are being considered next generation in terms of energy storage systems. They have the highest energy storage efficiency that has been observed in comparison to previous devices. All kinds of clean tech are beginning to heavily rely on their usages, such as clean electric power and electric vehicles.
A key element of managing supercapacitors and batteries is that of monitoring their working state, and last year researchers in China and Canada teamed up to develop a new system that relies upon fiber optics to reliably observe their state of charge.
Current methods for monitoring the state of these storage devices, and reporting on their performance and operation quality are not up to scratch. They can’t offer real-time information on charge state while the devices are in operation. To get a reading, supercapacitors must be taken offline for electrical measurements to be taken, which sometimes involves opening up the devices to use electron microscopy to study the components. These methods are time-consuming, interruptive to function, and inefficient. They do not do what they need to do, which is giving instant and continuous readings of charge and performance.
For this reason, the team at Jinan University, which included researchers Tuan Guo and Wenjie Mai, innovated a new method of monitoring energy storage, which is based on an optical fiber-based plasmonic sensor. The team developed a strategy where an embedded fiber optic sensor near to the surface of the capacitor electrodes is used to measure the level of charge of the electrodes and electrolytes during operation. The sensors feedback the fluctuating state of charge in real-time through the telecommunication-grade fibers, allowing for remote monitoring at a distance.
In addition to the benefit of providing data in real-time, the new system by the team at Jinan University relies on direct measurements, rather than indirect estimations. Current techniques rely upon current/voltage tests that can only measure indirect estimates of the state of charge. This innovation, on the other hand, uses the optical fiber to directly measure the impact on the plasmonic properties of the fiber’s gold coating through detecting the accumulated charge in layers over the electrodes and electrolyte.
The method has been tested to show high correlations between readings of the optical transmission of the fiber device and the supercapacitor's charge state. This indicates that the method can be used as a low cost and reliable measure of charge that can relay information in real time, remotely. The future of energy storage can expect to be impacted greatly by this development which will allow for more accurate monitoring of supercapacitors, which will assist as global sectors make the switch from fossil fuels to renewable energy sources.
References and Further Reading