Lattice-Prestressed Niobium Tungsten Oxide Enables Near-Zero Volume Change and Ultrafast Lithium Storage

Niobium tungsten oxide offers rapid ionic transport and high safety in fast-charging lithium-ion batteries, but suffers from challenges of large structure stresses and low capacity retention at rates exceeding 20C. Here, a novel lattice-prestressed Nb 14 W 3 O 44 (LP-NWO) is reported that overcomes its intrinsic structural limitations, enabling near-zero volume change and ultrafast lithium storage. The lattice-prestressed structure involves the alternating distribution of 4 × 4×∞ and 4 × 3×∞ rectangle units, along with octahedra distortion, which leads to the formation of specific and ordered lattice prestresses. The rectangle units induce tensile stresses, while the octahedra distortion results in compressive stresses. This prestressed structure not only preserves continuous diffusion channels but also enhances both ion and electron conductivity. Importantly, the presence of prestress greatly relieves the strain generated during lithium insertion and extraction. This can be observed through a reversible curve-to-straight evolution of lattice fringes, resulting in near-zero volume change during cycling. The LP-NWO delivers a 78% capacity retention at 100C after 20 000 cycles and more than 2 000 cycles of full cells at 50C, as well as no safety risk under severe stress conditions. This prestressed strategy offers implications for the development of zero-strain electrodes, aiming to overcome fast-charge limitations through internal means.