An expert view on the electric vehicle batteries of tomorrow
In this edition of Beyond Bax, we speak to Jordi Jacas Biendicho, a staff scientist at IREC (the Catalonia Institute for Energy Research) and coordinator of COBRA, a new European initiative on next-generation sustainable lithium-ion electric vehicle batteries. We discuss the current state of the electric vehicle battery landscape and COBRA’s promising technologies.
High-performing energy storage devices such as batteries play a vital role in the transition to clean energy, since they can balance the often fluctuating capacity of renewable sources. Extensive research has been done in the past decade to improve battery performance in capacity, flexibility, efficiency, cycling stability, as well as decreasing their cost and impact on the environment. As a result, the current market of rechargeable batteries is mainly dominated by high-energy-density Li-ion batteries. However, a drastically rising demand, largely driven by the electrification of mobility, is challenging battery researchers to come up with new developments to minimise their social, environmental and other impacts.
Which challenges need to be overcome to reach the full potential of Li-ion batteries, without creating adverse social or environmental impacts?
JJ. There are several challenges to be addressed in order to achieve the full potential of Li-ion batteries. Improving their performance, e.g. increasing capacity and enabling faster charging compared to current batteries would make them better suitable for an increased range of applications. This would be a major driving force for higher adoption which involves many aspects, from improving individual battery components to manufacturing processes. Cost is also a critical factor. Cheaper components and manufacturing processes for upscaling new battery technologies are indeed required to achieve the full potential of the batteries. Nevertheless, performance and cost should be evaluated together with environmental and social aspects as a whole, to achieve sustainable integration of Li-ion batteries into society.
You mentioned improving battery performance as one of the main challenges. What would you consider as the main research focus areas to improve this?
JJ. Improving the performance of batteries involves many aspects. Speaking in broad terms, materials development is always the first step. Many materials have been proposed to increase battery capacity but only a few have reached commercialisation owing to their excellent performance and availability, in the same way as new electrolyte formulations and separators. Advanced manufacturing, smart monitoring, and management systems are also key research areas to be improved for next-generation Li-ion batteries. Advanced manufacturing is critical in maximising the energy density for a given system, and smart monitoring and management systems ensure better performance and an extended lifetime for a battery.
How are these and other key research areas dealing with sustainability and social issues?
JJ. Environmental and social aspects are indeed considered within research areas mentioned above, aiming to achieve a more sustainable battery for the future. Certain chemicals or metals exist in limited quantities, are highly toxic or have ethical issues related to their mining and processing. These factors should be critically assessed during the material development and manufacturing stages. Recyclability is also an important aspect to be considered at all levels up to battery second-life. These aspects are typically assessed through a Lifecycle Assessment during the early research stages of new technologies, which provide an understanding of the environmental, societal, and financial impacts of upscaling a given technology.
How is your work in COBRA solving some of the above mentioned challenges while minimising negative impacts?
JJ. COBRA aims to develop a novel Li-ion battery technology that overcomes many of the current shortcomings faced by Electrical Vehicle (EV) batteries. An innovative cobalt-free cathode technology is proposed with increased capacity compared to current electrodes. For the anode, we are looking at silicon-based composites obtained from waste streaming recycling and able to achieve long-life performance. The electrolyte stability and safety are also critical points considered in the project. For all the components, we have introduced LCA studies at the early stages to ensure minimal negative impact on the environment. At cell level, we have several tasks aiming to improve performance while reducing cost; from an improved electrolyte filling to a better cell formation process.
One of our aims is to compare as-proposed developments by producing different cell generations and, together with environmental inputs, select best-performing ones for the final generation or GENX. Equally important is the research conducted at battery pack level involving the integration of sensors, battery management and testing and validation since the final scope of the COBRA project is to deliver a demonstrator with a very specific cost target of no more than 90 €/kWh. The development of the battery management system for enhanced performance includes improved battery state estimation algorithms, battery charge management and degradation modelling derived from the network of smart sensors. A specially designed battery holder using green or recycled materials will be constructed to improve safety.
Overall, the COBRA project targets next-generation Li-ion batteries using a sustainable approach, from minimising the use of critical raw materials at all component levels to exploring the recyclability of the packs for second-life, having performance and cost as key challenges.
Looking ahead, what do you see as the most disruptive innovation (in terms of technology and materials) within the battery landscape for electric vehicles in the next 10 years?
JJ. There are several technologies which are currently being investigated for future electric vehicles in addition to Li-ion batteries. The Li-Sulfur technology is a promising one because of its higher capacity per unit mass and reduced cost due to the use of sulfur, but it needs to overcome several drawbacks such as poor cycle life at cell level, in order to become a commercially viable technology.
Other technologies are solid-state batteries and metal-air batteries which, from my point of view, are currently at a low technology readiness level (TRL). The former is interesting because it can take advantage of the material developments currently on-going for Li-ion batteries, with improved safety and energy density since there is no liquid component. The metal-air battery is a hybrid system between a battery and a fuel cell. It uses an external source of fuel and oxygen (usually from air) to sustain the chemical reaction. Metal-air batteries are interesting because, in theory, they could boost the driving range of electric cars beyond gasoline.
Last but not least, I would like to mention the supercapacitor technology which is expected to significantly increase its energy density in the near future.
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At Bax & Company, we’re lucky enough to work with experts in emerging and existing fields from around the world. Beyond Bax is an opportunity for us to share some of their knowledge with you.
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