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Modern electric cars with large batteries can now offer ranges of over 500 kilometres. It has now been claimed that a new type of battery technology will make it possible to travel up to 2,000 kilometres with just one charge. The new battery cells are expected to be in use by 2023. Volker Blandow, Head of e-Mobility at TÜV SÜD, is here to answer some questions on the topic.
V. Blandow: Up to now, every new battery technology that has been hyped up has had some issues, so that the incremental improvement of the existing technology has remained the way how progress in batteries materialized. One may also not forget that a new technology always also has to be compliant with existing production facilities and their proven tools for reliable mass manufacturing. But I would be really pleased to see the capacity increase by up to four times, as it would resolve many of our problems. Despite this, the progress is notable when you consider what Tesla presented at the Battery Day for 2022: a half-priced battery offering considerably improved capacity.
V. Blandow: There is no question that the surfaces hold a great deal of potential. All battery manufacturers are currently working on the electrode surface coatings. The increased requirements concerning rapid charging demand that all components have an extremely high conductivity. This is because, if the resistance is too high, too much heat is produced. The problem here is that this makes the battery less safe. “In and out quickly” is not good in the case of a fault. Lots of additional things need to be considered, for example durability, cost and response to mechanical stress. How stable is the chemical coating and what happens when high power charging becomes more and more frequent?
V. Blandow: All-solid or semi-solid technologies promise lots of benefits, but at the moment there are still a lot of challenges to be overcome. There is a reason why liquid electrolytes have been successful by now. Due to their physical behaviour they guarantee a very robust electrical connection between the electrodes. All solid surfaces must have perfect conductivity between electrodes and electrolyte, this is mainly achieved through mechanical pressure and smart surface technologies. However, this mechanical connection needs to survive a full automotive lifecycle with high and very low temperatures, vibration, and mechanical stress due to charging/discharging cycles. A small “crack” might lead to electrical hot spots and inhomogeneous distribution of electrical current. Semi-solid might be a good solution on the way to true “all solid” batteries. TÜV SÜD is very committed to support the development of solid-state batteries, our global expertise out of 10 existing battery labs can provide a lot of experience in evaluation and whole lifecycle assessment of new battery technologies.
Source: AUTO SERVICE PRAXIS
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