High-volume capacity electrode materials are the key to the development and application of lithium-ion batteries in electric vehicles and small consumer electronics. Here, through simply calcination the W-based metal-organic frameworks, a novel Fe₂WO₆ hierarchical porous octahedra with oxygen vacancies are successfully constructed. Oxygen vacancies can enhance the conductivity of the material, provide more Li⁺ storage sites, while the hierarchical porous structure effectively buffers the volume expansion and promotes the diffusion of the electrolyte. Besides, by introducing the heavy element W, the compact density of Fe₂WO₆ is as high as 2.9 g cm⁻³. Thus, an ultrahigh volumetric capacity of 4785 mAh cm⁻³ (0.2 A g⁻¹), and superior rate capability of 2323 mAh cm⁻³ (4.0 A g⁻¹) could be achieved by Fe₂WO₆ anode, which is the best performance of W-based anode so far. Furthermore, the mechanism of the significant increment in capacity is also investigated. The new findings indicate that the phase transition and structural rearrangement of the Fe₂WO₆ electrode, along with the enhanced reversible formation and decomposition of the polymer/gel-like film, collectively result in the capacity evolution during cycling. Remarkably, the introduction of oxygen vacancies and high density makes hierarchical porous Fe₂WO₆ a promising anode for high volumetric lithium storage.

大容量电极材料是锂离子电池在电动汽车和小型消费电子产品中开发和应用的关键。在这里，通过简单地煅烧基于W的金属有机骨架，就成功地构建了具有氧空位的新型Fe ₂ WO ₆分级多孔八面体。氧空位可以增强材料的电导率，提供更多的Li ⁺储存位，而分层的多孔结构有效地缓冲了体积膨胀并促进了电解质的扩散。另外，通过引入重元素W，Fe ₂ WO ₆的致密密度高达2.9g cm ^-3。。因此，通过Fe ₂ WO ₆阳极可以实现4785 mAh cm ^-3（0.2 A g ^-1）的超高体积容量和2323 mAh cm ^-3（4.0 A g ^-1）的超高倍率容量。迄今为止W基阳极的最佳性能。此外，还研究了容量显着增加的机制。新发现表明Fe ₂ WO ₆的相变和结构重排电极，以及增强的可逆性聚合物/凝胶状薄膜的形成和分解，共同导致循环过程中容量的演变。显着地，氧空位和高密度的引入使得分层多孔Fe ₂ WO ₆成为用于高容量锂存储的有希望的阳极。