Published: 25.07.2023
Tomáš Syrový, a scientist at the University of Pardubice, is working on a new generation of smart batteries that could monitor their capacity and restore it if necessary. They could be used, for example, in electric cars or stationary battery storage systems.
"Sensors surround us today in all our activities; they help to prolong life or improve its quality but also to save energy and prevent accidents," says Tomáš Syrový from the Faculty of Chemical Technology, University of Pardubice.
You are now working on how to improve the batteries. How are you going to do that?
It applies to accumulators that are intended for electric vehicles but also for stationary storage. We want to develop batteries that have extended functions. They will contain sensors inside the cells themselves.
For example, the "shelf sensor" is used to detect the occupancy of shelves in refrigerators. It's a pad in the fridge, and we can see the occupancy of the fridge down to every single can of beer thanks to it and its connection to IoT networks. Plzeňský Prazdroj then sees in the "cloud" how people shop and which products they are interested in.
But this is not so new.
Yes and no. Accumulators typically have external temperature or pressure sensors that are outside the case. But I'm going to deal with the sensor that will be inside the battery. They are in direct contact with the accumulator's electrolyte, and with such "internal" sensors, we can measure a variety of parameters not otherwise measurable. In particular, we aim to use them to determine the "state of health" of the batteries. That will be measured, for example, by a type of sensor that we have already patented, which determines the concentration of specific ions, because these are released during the cycling of the accumulator. When their concentration rises above a certain limit, we know something unsuitable is happening inside. The project aims to research and develop these sensors, but also the self-correcting properties of the accumulator electrodes, which can reverse undesirable processes when the sensor detects an undesirable condition. Importantly, these sensors must be able to monitor the state of the battery for at least thousands of cycles to monitor the SoH throughout the battery's lifetime.
I guess you answered part of my other question at the end of your answer. How long will the battery's life be extended if you check its condition with a sensor?
It can be a major change. I cannot comment on research activities to reverse the processes inside the accumulator now, but we can extend the battery's life by at least tens of per cent.
So, these sensors inside the accumulator are quite crucial for developing electromobility.
They are. It is an issue that will drive the research and development of the next generation of accumulators, the so-called smart accumulators, where not only the quality of the material on the anode and cathode side is being improved, solid-state electrolytes are being deployed, but above all, the direction of development is towards diagnostics inside the accumulator. Therefore, we are interested in what is happening inside, preferably in real time. Knowing the moment when something has gone wrong in the battery, whether low-temperature charging or high-temperature charging is to blame for the accumulator failure or whether the battery has received some other shock, is important, at the very least, both for future action and for an immediate effort to minimise the impact.
We cannot detect such information in today's accumulator, as only sensors on the outside of the pack are often used to measure temperature or pressure. By putting the sensors inside the accumulator, we can monitor what is happening inside, which is a significant shift. By detecting undesirable phenomena early, we can use approaches to minimise or reverse these adverse conditions.
Could it reduce battery fires in electric bikes?
I'm sure. Thanks to developing a specific sensor, we are also targeting these problems. We will design a type of sensor that should detect those first "messengers" that prevent subsequent undesirable phenomena such as battery ignition.
How do you achieve sensor endurance in the accumulator? What are the most significant research challenges with these sensors?
In addition to the sensitivity and selectivity of the sensors themselves, it is their stability that is related to their endurance. We can also design the composition of the sensors. They must be very robust because the battery has an "electrochemical hell" inside, like very aggressive solvents, carbonates or ethers, and salts. In addition, due to the very high cell voltage, electro-corrosion can occur, leading to the degradation of many sensor materials and subsequent chemical destruction. However, with a lot of experience researching resistant sensor materials, we can deal with this "the Czech way". The project will develop both the electrode materials, which are supposed to have restorative capabilities and the sensors. All of this together will move the battery forward. In fact, we're developing a smart battery module.
You are one of the members of this international project. What is your role, and who do you cooperate with?
My activity is focused on researching these sensors printed in roll-to-roll mode, i.e. on the large-scale production of such sensors to make their production cheap and repeatable. Thus, the development of materials, geometry, but also the technology of sensor production. However, I will also be assisted by our partner sites. There are a number of prestigious battery research institutes, such as the Institute for Energy Technology from Norway, KI Ljubljana, the University of Uppsala, the University of Warwick, Fraunhofer ISE, and many others. Salamander is a European Commission project with support from the Battery 2030+ initiative.
But you have developed a lot of other sensors that have been deployed practically for some time.
Yes. For example, the "shelf sensor" detects shelf occupancy in refrigerators. This sensor is a kind of pad in the fridge, and thanks to it and its connection to IoT networks, we can see the occupancy of the fridge with the accuracy of every single can of beer. There are currently 70 supermarkets across the country that are so equipped. Plzeňský Prazdroj then sees in the "cloud" how people shop, which products they are interested in, whether the fridges are filled, etc. These sensors have been running in real life for two years and are very stable.
Let's move on to the other sensors you are involved in.
Using printing technologies, we are also developing sensors for soil moisture detection with the Crop Research Institute and the University of West Bohemia. The sensor is printed on wood using a special carbon composite. It can monitor soil moisture at two different soil depths, which is interesting both from the point of view of controlled irrigation and for long-term monitoring of soil moisture to see how it rained in a given area during the season. The data is calculated using electronic units, again handled by our colleagues at the university.
There is a sensor even in the nappy.
It is the sensor we developed for long-term patients with COC Ltd. Our printed sensor technology allows you to upgrade the features in a normal incontinence nappy. It enables measuring the nappy's contents after tens of per cent filling. When the patient is lying down, the nurse can see on the monitor that the lying person's nappy is perhaps sixty per cent full, and it is appropriate to change it. This way, nappy rash is prevented. But there is another dimension, where patients are relieved of having someone physically look into their nappies, which is undoubtedly uncomfortable for anyone. It is also important from the point of view of staff efficiency, where, thanks to smart nappies, staff only change the nappy of patients who need it or can see their condition remotely. Another positive impact is that patients do not have to be physically checked every two hours, and they get better sleep, positively affecting their health.
Will people in the Czech Republic get to see it?
I'm sure they will. Our Dutch partner is around with their products, so it's just a matter of time. The partners want to assess everything carefully in sight in the Netherlands, and afterwards, it will certainly get global, including here.
Can the sensor be applied to everything?
Basically, yes. When someone wants to monitor something, it's a matter of coming up with some chemical or physical principle to indicate the parameter being monitored and converting it into, for example, an electrical quantity or a colour sensation when it's supposed to be monitored visually.
I suppose your household can't do without sensors, either.
Well, it can't. (smile) I have an ecosystem at home with forty to fifty elements that contain sensors for light, humidity, and temperature. I use them to switch appliances on and off depending on the sunshine, how charged my battery is, or if I'm charging my car. I'm trying to create home automation and set it up to increase energy use efficiency, but at the same time, not to bother my family with that optimisation. It's kind of another experimental thing that I'm working with.
When the sun is shining, and I have the battery charged, I run an appliance that uses the current energy rate produced. Sensors are essential for that automation, and I've figured out how many more I need in that home ecosystem to make it more efficient. We have developed many sensors that could be used in combination with circuit breakers and outlets. It's just a matter of time before I deploy more of them at home, at least in experimental mode. We are currently testing one sensor for water leak detection, an integrator, which we are working on with Demcak s.r.o.
How are sensors physically created?
We print using conventional printing technologies such as screen printing and flexography, but also 3D printing techniques or conformal printing techniques – i.e. printing on 3D surfaces. It is only natural that we also create sensors by printing. Printing technologies have high production speeds and excellent repeatability when the technology is mastered well. For example, we print the aforementioned nappy sensors directly onto a nappy film 1.3 meters wide, which allows us to print 600 sensors per minute with a size of 0.3 x 1 m. That said, we print at a speed of 200 meters per minute.
Does your research in sensors have an impact on teaching? I noticed you are preparing a new course at the University of Pardubice focusing on new and related technologies. What is it going to be like?
Indeed, during the studies, our students encounter the issue of material printing in their courses and final theses, where the area of printed sensors is quite common. This issue will also be more emphasised in the new professional bachelor's degree program called "Modern Printing and Visualization Technologies", which we have completed in the past weeks and is now in the evaluation phase. New printing areas will be seeping in alongside conventional printing technologies and processes. The curriculum will also educate students in 3D printing, 3D scanning and 3D visualisation using VR, technologies that enable the creation of innovative products.
Overall, the curriculum is designed to give students higher practical skills in various areas of printing and visualisation technologies. It provides graduates with better opportunities for subsequent job placement, i.e., they can also find employment in the emerging 3D printing industry or industries increasingly adopting printing technologies, such as mechanical engineering, electrical engineering, construction, and others. If the course passes the evaluation process, we will start accepting applications as of 1 November 2023. We will open this three-year bachelor's degree programme for the 2024/2025 academic year.
