High-energy batteries made from lithium-rich cathode materials suffer from several bottlenecks, including large voltage hysteresis. Researchers in Amiens and Paris led by Charles Delacourt of the Université de Picardie Jules Verne and Jean-Marie Tarascon from the Réseau sur le Stockage Electrochimique de l’Energie (RS2E) and the Collège de France have now studied this phenomenon by directly measuring the heat generated by Li/Li2Ru0.75Sn0.25O3 (Li/LRSO) cells during various cycling conditions using a technique called isothermal calorimetry. LRSO is a “model” Li-rich layered cathode.
They have shown that this heat is thermodynamically related to the lost electrical work crucial for practical applications. They also reveal that the electrochemical oxidation/reduction of the anions is immediately followed by a structural rearrangement of the material to stabilize the reduction.
The work, published in Nature Energy, could help pave the way to reducing voltage hysteresis, minimize heat dissipation and achieve 100% energy efficiency in lithium-rich cathodes for next-generation batteries, says the team.
Read the research paper: Probing the thermal effects of voltage hysteresis in anionic redox-based lithium-rich cathodes using isothermal calorimetry. Gaurav Assat, Stephen L. Glazier, Charles Delacourt, Jean-Marie Tarascon. Nature Energy 10.1038/s41560-019-0410-6.