Spinel lithium titanate (Li₄Ti₅O₁₂) is the most promising negative electrode material for energy storage which can be applied in lithium-ion batteries lithium-sulphur batteries, and supercapacitors. However, the high cost of Li₄Ti₅O₁₂ powder and its high molecular weight limit its application due to the complicated synthesis process. In this work, a facile solid-state reaction in a fluidized bed reactor was used for the first time to synthesize spinel Li₄Ti₅O₁₂ using lithium carbonate and titanium oxide as solid reactants. We investigated the fluidization behaviour of starting materials and studied different synthesis temperature in fluidized and fixed beds. X-ray diffraction and scanning electron microscopy were employed to characterize the samples. The results demonstrate that the mixture of Li₂CO₃ and TiO₂ had a complete fluidization velocity of 0.88 cm/s and showed good fluidization behaviour. Pure spinel Li₄Ti₅O₁₂ was obtained via solid-state reaction in a fluidized bed reactor at 800°C for 30 minutes, which is much lower than a conventional solid-state reaction in a fixed bed or muffle furnace. By this novel method, the micro-sized Li₄Ti₅O₁₂ particles (6-8 μm) have hollow porous structure composed of nano-sized particles (<100 nm) synthesized. According to the experimental results, we proposed a different reaction mechanism for the synthesis of Li₄Ti₅O₁₂ in fluidized beds which explains how the Li₂CO₃ and TiO₂ react to form hollow lithium titanate nano-structured micro-particles in fluidized beds. The bulk density, surface area, and bulk conductivity of the synthesized Li₄Ti₅O₁₂ are 3240 kg/m³, 4.6 m²/g, and 3.90 × 10⁻⁶ S/cm, respectively.

中文翻译：

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Li4Ti5O12负极材料在流化床热重分析仪中的合成

尖晶石钛酸锂（Li ₄ Ti ₅ O ₁₂）是最有前景的储能负极材料，可应用于锂离子电池、锂硫电池和超级电容器。然而，Li ₄ Ti ₅ O ₁₂粉体成本高，分子量大，合成工艺复杂，限制了其应用。在这项工作中，首次使用流化床反应器中的简易固态反应合成尖晶石 Li ₄ Ti ₅ O ₁₂使用碳酸锂和氧化钛作为固体反应物。我们研究了原料的流化行为并研究了流化床和固定床中不同的合成温度。X射线衍射和扫描电子显微镜被用来表征样品。结果表明，Li ₂ CO ₃和TiO ₂的混合物具有0.88 cm/s的完全流化速度并且表现出良好的流化行为。纯尖晶石 Li ₄ Ti ₅ O ₁₂通过在流化床反应器中在 800°C 下固态反应 30 分钟获得，这远低于在固定床或马弗炉中的常规固态反应。通过这种新方法，微米级Li ₄ Ti ₅ O ₁₂粒子（6-8 μm）具有由合成的纳米级粒子（<100 nm）组成的中空多孔结构。根据实验结果，我们提出了在流化床中合成 Li ₄ Ti ₅ O ₁₂的不同反应机理，这解释了 Li ₂ CO ₃和 TiO ₂在流化床中反应形成空心钛酸锂纳米结构微粒。合成的Li ₄ Ti ₅ O ₁₂的体积密度、表面积和体积电导率分别为3240 kg/m ³、4.6 m ² /g和3.90×10 ^-6  S/cm。