Introducing large-radius elements in layered perovskite for low-voltage lithium storage

Abstract

Ti-based oxides usually exhibit the merits of excellent intrinsic safety, stable crystalline structure during electrochemical cycling, superior rate performance and abundance resources, making them attractive anode materials for high-performance lithium-ion batteries. However, most reported Ti-based anode materials usually show unsatisfactory energy densities, which is attributed to their relatively high working voltage (∼1.2 V–1.7 V vs. Li⁺/Li). Herein, we investigated the use of a new Ti-based oxide, LiSmTiO₄ (LSTO), as an anode material for lithium-ion batteries, which showed representative low-voltage lithium storage. Benefiting from its low working potential (∼0.3 V), the synthesized LSTO exhibited a high capacity of 243 mA h g⁻¹. In addition, this character resulted in a higher specific capacity and output voltage when paired with the same cathode. Moreover, the LSTO anode material delivered an excellent cycling performance, which is ascribed to the introduction of large-radius elements in the layered perovskite, effectively suppressing the tilt and displacement of its polyhedral networks. Therefore, the synthesized LSTO with a low working potential is a more balanced anode material than the well-known Li₄Ti₅O₁₂, showing great practical application prospect as a high-performance anode material. This study also offers a strategy to design new layered perovskites for low-voltage lithium storage.