The lithium-ion batteries on which countless devices depend today, from our phones to electric vehicles, have been around for more than 30 years and have become an essential component of current and future technologies.

Knowing their availability, longevity, performance and capabilities is now vital for users. But it is difficult to know these essential variables with certainty.

The question arises: should we trust the information that some devices such as the iPhone or any other mobile phone – or an electric vehicle – give us about the state of health of the battery? In other words, are we sure that the battery won’t let us down just when we need it most?

“Life” and “death” in one circuit

Lithium-ion batteries are made up of cells, each containing a positive and a negative electrode. These are immersed in an electrolyte that acts as a conductor to transport the ions. In this way, the electrons travel through the external circuit that powers the electrical devices and makes them work.

In the process, the batteries are discharged and have to be recharged again. This is called a cycle, and, like any other battery, the more cycles they experience, the sooner they “die”.

Studies measure how many cycles the battery lasts under certain electrical conditions. Unfortunately, changing factors such as operating temperature, charge/discharge rate and usage time lead to different lifetimes, making it really difficult to establish the health of batteries over time.

Will it be possible to estimate when a battery will cease to be operational, and what functionality it may have once it has reached the end of its life?

Digital twins

Industry 4.0 has been working on virtual simulation technologies since mid-2010, on so-called digital twins. These are sets of virtual information that fully describe a physical product.

In this area specifically, a lot of progress has been made in the development of simulation programmes for both the design of industrial plants and the virtual recreation of their processes.

These “twins” aim to analyse, optimise and improve the productivity of a plant in real time, reducing development times and detecting faults early.

With the right software, everything from industrial plants to devices such as batteries can be simulated. And thus have an exact digital reality in which to contrast the information recorded in the digital twin with that implemented in the battery management system.

This makes it easier for them to operate with maximum efficiency and ensure greater durability, as well as exploring their performance at specific moments, avoiding failures and even addressing possible optimisations.

Overly simple models

The problem is that batteries are very difficult systems to model faithfully.

Generally, indicators are used that are sometimes not directly measurable, such as the State of Charge (SOC), which represents the amount of charge the battery has compared to the maximum possible, and the State of Health (SOH), a parameter that assesses the performance of a battery compared to its ideal conditions.

Thus, the models are still too simple and their characteristics depend on the different types of batteries, their design and their type of manufacture.

Therefore, the accuracy of the indicators described above decreases, and not precisely in a linear way, and this must be taken into account in the operation of energy storage systems.

The BEST project

From Institute IMDEA Energía and the University of Alcalá de Henares, we are entering the field of digital twins for batteries with the Battery Energy Storage Digital Twin (BEST) project, funded by the Spanish Ministry of Science and Innovation.

In this initiative we propose the use of digital battery twins through the integration of mathematical models and health status estimators, as well as the analysis of operating data using artificial intelligence techniques.

This will provide greater knowledge and control over the real conditions of the battery systems throughout their operating life, thus reducing the differences that may exist between the definition of the model and the real system.

These differences generally arise either when the passage of time affects the characteristics of the batteries, or when an accurate model cannot be produced, or when working with a detailed model is not possible or is ineffective.

As a strategy, we have chosen a twin that brings together different techniques and allows us to achieve this purpose by creating a dynamic model with two approaches:

• The first is the reproduction of the state of health of the batteries based on the estimation of the state of the most relevant indicators of the cells (the aforementioned SOC and SOH).
• The second is the development of battery degradation models, obtained through a proper characterisation of cells of different chemistries and electrochemistry (lithium-ion power and capacity batteries, including other types of batteries such as redox flow batteries).

This, integrated with an analysis of operating data using artificial intelligence techniques, will provide much more complete and useful information on the actual condition of battery systems.

With this framework, it would be possible, for example, to calculate when they will reach the end of their life cycle and determine their state of health, either to find an efficient recycling method or to give them a second life in a less demanding application.

If it works, we would have come up with nothing less than a way to avoid suddenly running out of battery on our mobile phone and, secondarily, ending up with the excuse of blaming the battery for being late for a meeting or not answering a message on time.

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For yet another year, IMDEA Energía has actively participated in the Madrid Es Ciencia Fair, a major science dissemination event aimed at school communities and the general public.

Several of the centre’s researchers brought their work to Hall 5 of IFEMA Madrid through different experiments, workshops and participatory games over three days.

Thus, on Thursday 23 March, researchers from the Electrochemical Processes Unit and the Advanced Porous Materials Unit carried out practical activities on electrolytes, the manufacture of button cells and the decontamination of water using metal-organic networks.

In addition, Sergio Pinilla Yanguas, Catalina Biglione and Sergio Carrasco Garrido, postdoctoral researchers at the Institute, participated in the #MSCAFellow space of the Fundación para el Conocimiento madri+d, and on the Ágora stage.

On Friday 24th it was the turn of the Systems Analysis and Electrical Systems Unit. Attendees tested their knowledge of sustainable energy with a quiz and learned what a hybrid vehicle is and what the difference is between fast and slow recharging in an electric model through a board game in teams.

Javier Santaolalla also visited the IMDEA Institutes stand on this day to present the scientific dissemination platform Amautas, with the participation of several IMDEA Energy researchers involved in the project.

Finally, on Saturday 25th, the High Temperature Processes Unit team showed the participants some applications of heat generation by means of light by running a Stirling engine or melting chocolate with a homemade concentrator. In addition, virtual tours of our facilities were carried out using 3D glasses. For their part, researchers from the Photoactivated Processes Unit encouraged children to extinguish candles by generating CO2 and to make their own lava lamp with oil and water.

Thank you very much to everyone for joining us!

After three intense years of ground-breaking research, the EU research project NanoBat ends with revolutionary solutions for battery production in Europe and beyond. The consortium of 13 academic and industrial partners have jointly developed a novel nanotechnology toolbox for quality testing of Li-on and beyond Lithium batteries with a particular focus on the nanoscale structure of the SEI (solid electrolyte interphase) layer – an electrically insulated layer preventing ongoing electrolyte decomposition and responsible for battery performance and safety.

“With the new NanoBat technologies European manufacturers and SMEs will be adequately equipped to create a competitive manufacturing value chain for sustainable battery cells in Europe”, says project Coordinator Dr Ferry Kienberger from Austria-based industry partner Keysight Technologies.

The findings will impact various future endeavours: With the development of the now patented Keysight hardware EIS (electrochemical impedance spectroscopy), new products can be commercialised. The same is true for the QWED software modelling for integration in QuickWave and the newly established QWED GHz scanner. Further advances provide the base for future development. This comprises the high-throughput measure station developed jointly by Keysight and Kreisel, the fast electrochemical cycle test implemented at IMDEA, the new virtual quality gate data analytics prepared at Technische Universität Braunschweig, and the new scanning probe techniques designed by Ruhr-Universität Bochum and University of Burgos. Last but not least, Pleione Energy has established a battery pilot line for pouch cells and supercapacitors available to the wider battery community.

Over time, the green production methods can be scaled up through the involvement of global players in the automotive industry and spread to additional markets, such as speciality batteries for satellites, green buildings, GHz-materials or modelling software.

The findings will also foster the EU’s industrial competitiveness and innovation capacity and have a positive impact on the circular economy and the environmental footprint of battery production, as more precise testing methods result in a decrease of energy and raw material use and waste.

Further information on the results of the NanoBat project are available on the website (insert url) including short videos detailing the individual innovations.

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Project Key Facts

Title: NanoBat – GHz nanoscale electrical and dielectric measurements of the solid-electrolyte interphase and applications in the battery manufacturing line

Start: 1 April 2020

End: 31 March 2023

Budget: 4,966,912.50 €

Coordinator: Keysight Technologies GmbH, Austria

Website: www.nanobat.eu

Project Partners

• Austrian Institute of Technology GmbH, Austria
• Centro Ricerche Fiat, Italy
• EURICE – European Research and Project Office GmbH, Germany
• Federal Institute of Metrology METAS, Switzerland
• IMDEA Energy Institute, Spain
• Johannes Kepler University Linz, Austria
• Keysight Technologies GmbH, Austria
• Kreisel Electric GmbH & Co KG, Austria
• Pleione Energy S. A., Greece
• QWED, Poland
• Ruhr-Universität Bochum, Germany
• Technische Universität Braunschweig, Germany
• University of Burgos, Spain

Over the last decade, the process of decarbonisation of the energy system has intensified. Climate change and the need to reduce CO₂ emissions, on the one hand, and the development of clean, renewable and more economical technologies, on the other, have created the necessary conditions to replace traditional combustion sources with wind and photovoltaic energy.

The role of electricity grids is crucial in this process, as they provide the transport of energy to its point of consumption with minimum losses. In addition, in the future, electricity will be used much more in the transport sector, which will increase electricity demand significantly.

This scenario, together with the withdrawal of traditional generation due to decarbonisation, requires a substantial increase in production using more sustainable and cleaner energy resources.

How do electricity grids operate?

Since their inception, most of the production of electricity grids has been based on plants that convert thermal (either coal or gas or nuclear) or mechanical (hydro) energy into electricity, thus facilitating the transport of energy over long distances with few losses.

Large electrical generators connected to turbines are used for the conversion, whose inertia makes the electricity system robust and stable: it prevents blackouts in the event of serious disturbances, such as the disconnection of a generator or an area caused by human or natural causes.

With the aim of moving towards a decarbonised energy system, these types of generators are replaced by renewable sources.

At this point it is necessary to take into account that generation based on renewable sources is of lower power and more distributed characteristics. Instead of electrical machines, power electronic converters are used, which do not provide any inertial properties. In addition, the energy produced is time-variable and cannot be dispatched, thus requiring traditional back-up generators to achieve security of supply.

Towards a surplus of renewable production

All these factors have led to various technical and economic challenges in the field of integrating renewable energies into electricity grids and energy markets.

With the ambitious plans of all governments to decarbonise the energy system, more and more renewable sources will be connected to the electricity grids.

There will come a time, expected from 2030 onwards, when there will be a significant surplus of installed renewable capacity in Spain. It is expected that during the day it will even exceed demand.

There will come a time, expected from 2030 onwards, when there will be a significant surplus of installed renewable capacity in Spain. It is expected that during the day it will even exceed demand.

There will then be hours of excess renewable energy when the system will not allow all producers to generate at full capacity due to the configuration of the energy market, which defines the production mix.

What do we do with the surplus energy?

In those periods with possible excess production, what do we do with that energy? Do we waste it? Do we use it as a reserve? How can we compensate producers who have adjusted their generation or have to stop it?

One of the most obvious solutions is storage; however, it has both technical and economic limits. Although there are different energy storage technologies applied in electricity grids, in general there is very little storage capacity compared to the production capacity needed.

As Red Eléctrica explains, “electrical energy can be easily generated, transported and transformed, but it is difficult to store it in large quantities”. For this reason, electricity grids always make an instantaneous energy balance between production and demand.

Another option is to increase the use of demand management methods and the concept that demand follows production (the opposite of what we have today). Demand can be flexible, however, only within a certain range, so it cannot always provide the solution.

From the above, it is clear that the value of ancillary services in the grid will increase, especially those related to the robustness of the electricity system such as inertia and energy reserves.

If producers are enabled to offer these services, they could earn money not only in terms of energy produced, but also for services provided to the grid. This means that not all renewable plants will have to produce maximum power all the time, it will be sufficient that they are connected to the grid and available to ramp up or down the delivered power when disturbances in the system are detected.

To participate in these new markets for ancillary services, the control system of power electronics converters has to be adapted to the new requirements.

How to integrate renewables in a smart way?

Researchers at IMDEA Energía’s Power Systems Unit are working on the development of new control algorithms for power converters that serve as interfaces for renewable sources and batteries.

In particular, we are investigating a type of control called grid-forming, capable of emulating inertia (providing synthetic inertia) while supporting voltage and frequency control in power grids. These features enable renewable sources to become not only energy producers, but also grid service providers, harnessing excess capacity to strengthen electricity grids.

Our preliminary results are encouraging and demonstrate that in the future it will be possible to achieve the highest levels of reliability in power grids through improvements to the converter control system. However, certain changes in the regulatory framework are also needed, such as those related to grid connection rules and the functioning of energy markets and ancillary services markets.

Much research remains to be done to put the energy transition towards clean and renewable technologies on track. On this path, the main objective remains to ensure continuity and quality of supply for all ever-changing and increasingly demanding electricity demands.

More information: https://theconversation.com/llegara-un-momento-en-que-sobre-energia-renovable-que-haremos-con-el-exceso-201316

The IMDEA Energy Institute held three industrial sessions within the framework of the International Energy and Environment Fair GENERA 2023 on February 21^st, with the participation of prominent speakers from the business, academic and association environments that, together with those from IMDEA Energy, completed the Value chains:

• The Madrid+Circular Hub seed of technologies to valorize waste into products, which addresses an ambitious research program to create and develop a Circular Economy Hub, favoring the culture of cooperation between different agents of the science-technology-business system to generate and share knowledge about new technologies that facilitate the valorization of waste through its incorporation in industrial processes for the production of materials and fuels with a low carbon footprint, some of which require the incorporation of renewable hydrogen. Speakers from the companies Repsol, Ariema and EvoEnzime also participated.
• Sustainable fuels from digestion and fermentation waste integrating thermochemical, catalytic and biotechnological processes, in which it was discussed the integration of different innovative processes for the recovery of waste generated in the anaerobic digestion of different biodegradable materials (digestates) and the production of advanced bioethanol by alcoholic fermentation of non-food biomass (stillages) for its transformation into different types of sustainable fuels (bio-methane, bio-oils, bio-hydrogen and bio-coals) and other products of interest (fatty acids) reducing the volume of waste from biogas and bioethanol production. Speakers from Rey Juan Carlos University, Repsol, and Ingelia also participated.
• Present and future of decarbonization with concentrated solar termal energy in Spain, discussing the role to be played by concentrated solar thermal energy in the decarbonisation objectives in the different industrial sectors. Speakers from Protermosolar, Engie and Plataforma Solar de Almería, CIEMAT also participated.

Attendees exceeded one hundred, filling the room, some having to remain standing. The questions raised by the attendees and the debates provoked make it clear that the technologies covered are a hot topic of interest for specialists and the general public and a subject for further research and development projects.

The International Renewable Energy Conference, SPIREC, co-hosted by a national government and REN21, was held this year in Spain within the framework of Genera, with a technical visit to IMDEA Energy on February 23^rd, in which the solar field of heliostats, the pyrolysis and hydrodeoxygenation pilot plant and the SEIL grid emulation laboratory were shown. The visit was a success considering the interest aroused by the IMDEA Energy facilities and the lines of research, as well as the words and messages of the attendees.