According to a Nature paper, a modified charging design should help to prevent range fears – even with fewer kWh.
A Peugeot at an Amsterdam charging station (Image: Daniel AJ Sokolov)
One of the central problems in the implementation of e-mobility is still the comparatively long charging times when traveling over long distances. With new fast charging systems, this is being reduced more and more, but e-car owners still have to calculate significantly more time at the charging station than is known from filling up with petrol or diesel. The constantly increasing maximum range of electric vehicles only partially solves this problem.
Smaller battery, more charging – but faster
A research team at Pennsylvania State University (PSU) now wants to tackle the problem in an unusual way: their batteries are smaller, but thanks to a new charging design, they can be charged more quickly. Instead of a 150 kWh battery, 50 kWh models will be sufficient in the future. Since these are already full again in 10 minutes, the resulting reduced range should not be a problem. Other benefits include lower scooter costs because the battery is smaller; moreover, fewer raw materials are required for the production of the cells.
The PSU mechanical engineering professor Chao-Yang Wang wants to implement the idea together with the start-up EC Power, which also helped with the development. “The smaller, faster-charging batteries will drastically reduce battery costs and the consumption of critical raw materials such as cobalt, graphite and lithium, enabling mass adoption of affordable electric cars,” Wang said in a statement from the university.
Charging technology works with conventional batteries
The new charging method was published in a Nature paper. In it, Wang and his team write that it has long been a major challenge to quickly charge energy-dense rechargeable batteries such as the common lithium-ion batteries. Their approach is “material agnostic” but uses a thermally stable double salt electrolyte. In order to monitor what is happening in the battery, it is compared with a digital twin.
Keeping batteries at the right temperature while charging has been a major challenge for battery developers. However, external cooling and heating systems are not a solution, Wang believes. The central element of his charging technology is therefore what is known as internal thermal modulation, which works as an active method of temperature control within the battery. The researchers developed a new battery structure in which an ultra-thin nickel foil is used as the fourth component in addition to the anode, electrolyte, and cathode. The nickel foil acts as a stimulus and self-regulates the temperature and reactivity of the battery. In the laboratory, high charging speeds have been achieved in this way. EC Power is now investigating whether the process can really be commercialized.
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