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High‐voltage spinel‐type structured LiNi0.5Mn1.5O4 (LNMO) shows promise as a next‐generation high‐energy‐density lithium‐ion battery cathode material, however, capacity decay on extended cycling hinders its widespread adoption, underscoring an urgent need for further development. In this work, we introduce Zn at octahedral 16c crystal sites in LNMO with Fd3‾ ${\bar{3}}$ m space group to improve rate capability and reduce the rapid capacity decay otherwise experienced during extended cycling. The current work resolves the detailed influence of isolated modification at octahedral 16c crystal sites, unveiling the mechanism for these performance improvements. We show that occupation of Zn at previously empty 16c sites prevents the migration of Ni/Mn to adjacent 16c sites, eliminating transformation to a rock‐salt type structured Ni0.25Mn0.75O2 phase above 4.8 V, preventing structure degradation and suppressing voltage polarization. This study provides insights into the fundamental structure‐function relationship of the LNMO battery cathode, pointing to pathways for the crystal structure engineering of materials with superior performance. [ABSTRACT FROM AUTHOR]

Ion‐exchange materials are commonly composed of polyelectrolyte networks in which crosslinking preserves macroscopic geometry and prevents dissolution in aqueous conditions. However, crosslinking inherently inhibits efficient swelling and mass transfer during ion‐exchange processes. Herein, a one‐step polymerization‐induced microphase separation (PIMS) approach directly using water and linear polystyrene sulfonate macromolecular chain transfer agents (macroCTAs) is developed to engineer bicontinuous nanostructured materials with rapid ion‐exchange capabilities. These materials feature water‐swollen liquid‐like polyelectrolyte domain embedded in a rigid polymer network, where the domain spacing, as determined by small angle X‐ray scattering experiments, is precisely modulated between 15 and 89 nm based on the molecular weight of the macroCTA used. As the bicontinuous nanostructure enables rapid mass transfer throughout the material bulk, the 3D printed PIMS materials are able to rapidly remove model charged dyes from solution, exhibiting a mass transfer coefficient ≈35 times higher than commercially available counterparts. This work is the first example demonstrating direct self‐assembly of water into continuous nanochannels in a well‐controlled manner as supported by time‐resolved small‐angle neutron scattering experiments during polymerization. Moreover, these nanostructured materials are readily produced using commercially available 3D printers, enabling unparalleled high‐resolution fabrication of targeted complex structures, including accurately controllable macroporous geometries and surface areas. [ABSTRACT FROM AUTHOR]

Wadsley‐Roth niobium oxide phases have attracted extensive research interest recently as promising battery anodes. We have synthesized the niobium‐molybdenum oxide shear phase (Nb, Mo)13O33 with superior electrochemical Li‐ion storage performance, including an ultralong cycling lifespan of at least 15000 cycles. During electrochemical cycling, a reversible single‐phase solid‐solution reaction with lithiated intermediate solid solutions is demonstrated using in situ X‐ray diffraction, with the valence and short‐range structural changes of the electrode probed by in situ Nb and Mo K‐edge X‐ray absorption spectroscopy. This work reveals that the superior stability of niobium molybdenum oxides is underpinned by changes in octahedral distortion during electrochemical reactions, and we report an in‐depth understanding of how this stabilizes the oxide structure during cycling with implications for future long‐life battery material design. [ABSTRACT FROM AUTHOR]