Elucidating the crystal structures of the intercalation phases in KxCrSe2 (0=

The quest for affordable and sustainable energy storage has driven increasing interest in potassium-ion batteries (KIBs). However, metal chalcogenides have been largely overlooked as KIB cathodes due to the prevalence of side reactions during the intercalation process. Our recent research has demonstrated the feasibility of reversible K+ ion intercalation into CrSe2, achieving near-theoretical capacity in the resulting battery. This marks a significant advancement in the application of chalcogenides in KIB research. While the results are promising, challenges remain, including enhancing cycling stability and understanding structural changes during potassium intercalation. In operando studies are key in this regard, requiring access to synchrotron radiation since our laboratory attempts could not provide sufficient resolution and a reasonable 2θ range to elucidate the crystal structure changes occurring during the intercalation process.

对低成本且可持续储能技术的不懈追求，推动了钾离子电池（KIBs）领域的研究兴趣日益高涨。然而，由于插层过程中副反应频发，金属硫族化合物（metal chalcogenides）作为钾离子电池正极的应用长期被忽视。我们近期的研究证实了可逆钾离子（K+）插层进入二硒化铬（CrSe₂）的可行性，所制备的电池实现了接近理论值的储钾容量。这标志着硫族化合物在钾离子电池研究中的应用取得了重要进展。尽管该研究结果颇具前景，但仍存在诸多挑战，例如提升电池循环稳定性，以及阐明钾插层过程中的晶体结构变化机制。原位（in operando）表征是破解该类难题的关键，但此类研究需要依托同步辐射（synchrotron radiation）光源——实验室常规测试无法提供足够的分辨率与合理的2θ扫描范围，难以阐明插层过程中发生的晶体结构演变。