Phase Evolution of Multi‐Metal Dichalcogenides With Conversion‐Alloying Hybrid Mechanism for Superior Lithium Storage
Jingjing Jiang, Sanlue Hu, Xiangyong Zhang, Senlin Li, Hua Wei, Baohui Ren, Shizhen Li, Guangming Chen, Jinlong Yang, Cuiping Han, Zhuoxin Liu
Abstract
Abstract Traditional lithium‐ion battery (LIB) anodes, whether intercalation‐type like graphite or alloying‐type like silicon, employing a single lithium storage mechanism, are often limited by modest capacity or substantial volume changes. Here, the kesterite multi‐metal dichalcogenide (CZTSSe) is introduced as an anode material that harnesses a conversion‐alloying hybrid lithium storage mechanism. Results unveil that during the charge–discharge processes, the CZTSSe undergoes a comprehensive phase evolution, transitioning from kesterite structure to multiple dominant phases of sulfides, selenides, metals, and alloys. The involvement of multi‐components facilitates electron transport and mitigates swelling stress; meanwhile, it results in formation of abundant defects and heterojunctions, allowing for increased lithium storage active sites and reduced lithium diffusion barrier. The CZTSSe delivers a high specific capacity of up to 2266 mA h g −1 at 0.1 A g −1 ; while, maintaining a stable output of 116 mA h g −1 after 10 000 cycles at 20 A g −1 . It also demonstrates remarkable low‐temperature performance, retaining 987 mA h g −1 even after 600 cycles at −40 °C. When employed in full cells, a high specific energy of 562 Wh kg −1 is achieved, rivalling many state‐of‐the‐art LIBs. This research offers valuable insights into the design of LIB electrodes leveraging multiple lithium storage mechanisms.