Conductive M–Nb^V–O compounds are high-capacity, fast-charging, safe and stable anode materials that have potential use in lithium-ion batteries. However, their studies are very limited. Here, we facilely fabricate Nb₂₅O₆₂ (i.e., Nb^IVNb^V₂₄O₆₂) and Nb₁₂O₂₉ (i.e., Nb^IV₂Nb^V₁₀O₂₉) from high-temperature reduction of Nb₂O₅ in a mixed H₂/Ar atmosphere. Nb₂₅O₆₂ shows a monoclinic shear ReO₃ crystal structure with a C2 space group and a structural unit containing a 3 × 4 octahedron-block and 0.5 tetrahedron, while Nb₁₂O₂₉ shows a similar structure with an A2/m space group and a 3 × 4 octahedron-block. Their resulting open crystal structures lead to their large Li⁺-ion diffusion coefficients. Due to the unpaired 4d electrons in Nb⁴⁺, their electronic conductivities are increased by three orders of magnitude in comparison with Nb₂O₅. First-principles calculations even demonstrate their conductor characteristics. Hence, Nb₂₅O₆₂/Nb₁₂O₂₉ exhibits comprehensively good electrochemical performance, including a significant pseudocapacitive contribution (72.7/79.0% at 1.1 mV s⁻¹), high specific capacity (289/287 mAh g⁻¹ at 0.1 C), high working potential (∼1.69/∼1.72 V vs. Li/Li⁺), superior rate capability (133/165 mAh g⁻¹ at 10 C) and prominent cyclic stability (only 0.3/14.5% capacity loss over 1000 cycles at 10 C). These findings demonstrate that Nb₂₅O₆₂ and Nb₁₂O₂₉ are promising anode materials for future use in high-performance lithium-ion storage.

导电的M–Nb ^V –O化合物是高容量，快速充电，安全稳定的负极材料，可在锂离子电池中使用。但是，他们的研究非常有限。在这里，我们通过混合中高温还原Nb ₂ O ₅来方便地制造Nb ₂₅ O ₆₂（即Nb ^IV Nb ^V ₂₄ O ₆₂）和Nb ₁₂ O ₂₉（即Nb ^IV ₂ Nb ^V ₁₀ O ₂₉）。H ₂ / Ar气氛。铌₂₅ O_图62显示了具有C2空间群和包含3×4八面体嵌段和0.5四面体的结构单元的单斜切ReO ₃晶体结构，而Nb ₁₂ O ₂₉显示了具有A2 / m空间群和3×结构的相似结构。4个八面体块。它们产生的开放晶体结构导致其大的Li ⁺离子扩散系数。由于Nb ^4+中未配对的4 d电子，与Nb ₂ O ₅相比，其电子电导率增加了三个数量级。第一性原理的计算甚至证明了它们的导体特性。因此，Nb₂₅ O ₆₂ / Nb ₁₂ O ₂₉表现出全面良好的电化学性能，包括显着的假电容贡献（在1.1 mV s ^-1时为72.7 / 79.0％），高比容量（0.1 C时为289/287 mAh g ^-1），高工作效率电位（相对于Li / Li ⁺约为1.69 /〜1.72 V ），出色的速率容量（在10 C下为133/165 mAh g ^-1）和出色的循环稳定性（在10 C下1000次循环中仅0.3 / 14.5％的容量损失） 。这些发现表明，Nb ₂₅ O ₆₂和Nb ₁₂ O ₂₉ 有望用于高性能锂离子存储的阳极材料。