The advancement of lithium-ion batteries (LIBs) with high performance is crucial across various sectors, notably in space exploration. This advancement hinges on the development of innovative cathode materials. Our research is dedicated to pioneering a new category of cathodes using fluorinated multimetallic materials, with a specific focus on diverging from the traditional Ni, Co, and Mn-based NMC chemistries by substituting nickel and manganese with copper and iron which are more sustainable elements. Our goal is also to enhance the robustness of cathodes upon cycling by substituting oxygen with fluorine as the metal–ligand. To achieve this, an intimate composite blend of CuF₂ and FeF₃, through the multi-metallic template fluorination (MMTF) methodology using a layered double hydroxide (LDH) as a precursor has been designed. Each of these components was carefully selected for its distinct attributes, including high redox potential, elevated energy density, substantial theoretical capacity, and improved cyclability. The composition denoted as (Cu_1.5Co_0.5)²⁺(Fe_0.75Al_0.25)³⁺ has been selected for fluorination because it maximizes Fe³⁺ and Cu²⁺ amount in the screened LDHs. Subsequently, this particular LDH was fluorinated through solid–gas fluorination at different temperatures (200, 350, and 500 °C) using gaseous molecular fluorine (F₂). A comprehensive characterization of these materials using various techniques, including X-ray diffraction (XRD), ⁵⁷Fe Mössbauer spectrometry, scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), and inductively coupled plasma analyses (ICP-AES) was conducted, and the evolution of LDH upon fluorination has revealed an intermediate porous texture particularly sensitive to hydration. Two original crystallographic phases are else obtained by fluorination: one formed by the hydration of the amorphous intermediate compound: Cu₃Fe_1.5Al_0.5F₁₂(H₂O)₁₂ an anti-perovskite structure and another stabilized through the combination of solid gas fluorination and LDH precursor yielding an original CoFeF₅-type phase. Raman operando during cyclic voltammetry measurement applied on a sample fluorinated at 500 °C and used as a cathode in front of lithium metal was finally conducted to validate redox activity and mechanism.

中文翻译：

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将氟插入 LDH 模板后形成紧密混合的铜、钴和铁氟化物

高性能锂离子电池（LIB）的进步对于各个领域都至关重要，特别是在太空探索领域。这一进步取决于创新正极材料的开发。我们的研究致力于开创一种使用氟化多金属材料的新型阴极，特别注重区别于传统的镍、钴和锰基 NMC 化学物质，用更可持续的元素铜和铁替代镍和锰。我们的目标还在于通过用氟取代氧作为金属配体来增强阴极在循环时的稳健性。为了实现这一目标，通过使用层状双氢氧化物（LDH）作为前体的多金属模板氟化（MMTF）方法，设计了CuF ₂和FeF ₃的紧密复合混合物。这些组件中的每一个都根据其独特的属性进行了精心挑选，包括高氧化还原电位、高能量密度、大量理论容量和改进的循环性能。选择表示为(Cu _1.5 Co _0.5 ) ²⁺ (Fe _0.75 Al _0.25 ) ³⁺的组合物进行氟化，因为它使筛选的LDH中的Fe ³⁺和Cu ^{2+量最大化。随后，使用气态分子氟 (F} ₂ )在不同温度（200、350 和 500 °C）下通过固气氟化对这种特殊的 LDH 进行氟化。使用各种技术对这些材料进行全面表征，包括 X 射线衍射 (XRD)、⁵⁷ Fe 穆斯堡尔谱测定、具有能量色散 X 射线分析功能的扫描电子显微镜 (SEM-EDX) 和电感耦合等离子体分析 (ICP-AES)进行了，氟化后 LDH 的演变揭示了对水合作用特别敏感的中间多孔结构。通过氟化还获得了两种原始晶相：一种是通过非晶态中间化合物：Cu ₃ Fe _1.5 Al _0.5 F ₁₂ (H ₂ O) ₁₂的水合形成的，一种反钙钛矿结构，另一种是通过固体气体氟化的组合来稳定的和LDH前体产生原始CoFeF ₅型相。最终对在 500 °C 氟化并用作锂金属前面的阴极的样品进行循环伏安测量期间的拉曼操作，以验证氧化还原活性和机制。