Deciphering the role of van der Waals heterostructures in enhancing layered perovskite anodes for high-performance lithium-ion batteries

Abstract

Organic–inorganic hybrid halide perovskites have recently gained significant attention due to their outstanding optoelectronic properties. However, the application of halide perovskites in lithium-ion batteries (LIBs) is still in its infancy with inferior battery performance and an unclear reaction mechanism. This study presents a layered perovskite Li₂(C₂H₇NO₃S)₂CuCl₄ (LTCC) and deciphers the role of van der Waals heterostructures in high-performance anode materials for LIBs. The LTCC anode can achieve a remarkable specific capacity of 861 mA h g⁻¹ at 0.1 A g⁻¹ after 100 cycles. Moreover, it retains a high discharge capacity of 548 mA h g⁻¹ over 550 cycles at 1.0 A g⁻¹, exhibiting outstanding cycling stability among perovskite-type anode materials for LIBs. Comprehensive characterization studies illustrate the partially reversible conversion reaction of the LTCC anode to form CuCl, LiCl, and Li taurine during the lithiation process. Furthermore, experimental and theoretical results reveal that the unique van der Waals heterostructure of LTCC can enhance the structural stability and boost the Li-ion adsorption/transportation ability, thus accounting for the superior lithium storage performance. This study not only sheds light on the accurate electrochemical reaction mechanism of perovskite-type materials but also provides valuable insights for developing high-performance perovskite-based anodes for LIBs.