An Alternative Charge-Storage Mechanism for High-Performance Sodium-Ion and Potassium-Ion Anodes
Yanjiao Ma, Yuan Ma, Holger Euchner, Xu Liu, Huang Zhang, Bingsheng Qin, Dorin Geiger, Johannes Biskupek, Anna Carlsson, Ute Kaiser, Axel Groß, Sylvio Indris, Stefano Passerini, Dominic Bresser
Abstract
The development of suitable electrode materials remains a great challenge for alternative battery technologies such as sodium-ion and potassium-ion batteries; especially with regard to the negative electrode. Herein, Fe-doped CeO2 (Ce0.9Fe0.1O2−δ), which has very recently been introduced as a new anode material for lithium-ion batteries, is investigated as an insertion-type active material for the negative electrode of these alternative battery technologies, offering high specific capacity and very good rate capability in half-cells and full-cells. The complementary combination of experimental and computational methods allows directly relating the great capacity increase (by about 100%) to the off-centered Fe position and a selective reduction process, thus enabling substantially more sodium and potassium cations to be reversibly de-/inserted.