High cycle life all-solid-state fluoride ion battery with La2NiO4+d high voltage cathode
Mohammad Ali Nowroozi, Kerstin Wissel, Manuel Donzelli, Niloofar Hosseinpourkahvaz, Sergi Plana‐Ruiz, Ute Kolb, Roland Schoch, Matthias Bauer, Ali Muhammad Malik, Jochen Rohrer, Sergei I. Ivlev, Florian Kraus, Oliver Clemens
Abstract
Abstract Fluoride ion batteries (FIBs) are a recent alternative all-solid-state battery technology. However, the FIB systems proposed so far suffer from poor cycling performance. In this work, we report La 2 NiO 4.13 with a Ruddlesden-Popper type structure as an intercalation-based active cathode material in all solid-state FIB with excellent cycling performance. The critical charging conditions to maintain the conductivity of the cell were determined, which seems to be a major obstacle towards improving the cycling stability of FIBs. For optimized operating conditions, a cycle life of about 60 cycles and over 220 cycles for critical cut-off capacities of 50 mAh/g and 30 mAh/g, respectively, could be achieved, with average Coulombic efficiencies between 95 – 99%. Cycling of the cell is a result of fluorination/de-fluorination into and from the La 2 NiO 4+d cathode, and it is revealed that La 2 NiO 4.13 is a multivalent electrode material. Our findings suggest that La 2 NiO 4.13 is a promising high energy cathode for FIBs.