<p>The structural integrity of layered VOPO<sub>4</sub> frameworks critically determines their electrochemical performance in aqueous zinc-ion batteries, yet the highly ordered stacking of VOPO<sub>4</sub> renders it susceptible to lattice stress accumulation and chemo-mechanical degradation during cycling, causing rapid capacity fading and a shortened battery lifespan. Herein, we show a strategy to alleviate these limitations through partial metal substitution in the VOPO<sub>4</sub> lattice, enabling the modulation of local coordination environments and mitigating lattice and cycling induced stress. As a proof-of-concept, theoretical calculations and experimental validation on Mn-substituted VOPO<sub>4</sub> reveal shortened M–O bond along the c-axis and the formation of Mn–O–P–O–V delocalized structure. These modifications introduce subtle lattice distortions and generate percolation channels that enable more facile, ordered Zn<sup>2+</sup> migration, facilitating uniform lattice stress distribution. Real-time monitoring of interfacial stress during cycling identifies that Mn incorporation induces electronic redistribution and lattice anisotropy, promoting balanced intra-layer (a/b-axis) stress accommodation. Therefore, Mn-substituted VOPO<sub>4</sub> exhibits higher specific capacity and cycling stability, with 91.0% capacity retention over 2000 cycles at 1 A g<sup>−1</sup>. This intra-layer anisotropy engineering strategy offers a practical route for mitigating dissolution and strain effects during cycling, paving ways for the development of high-energy-density positive electrodes with cycling durability.</p>

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Anisotropy-mediated stress regulation in Mn-substituted VOPO4 enables aqueous zinc batteries with long cycle life

  • Zhenjie Yao,
  • Wenyao Zhang,
  • Xinyu Chen,
  • Junjie Cui,
  • Boyuan Zhu,
  • Jiahao Tang,
  • Yangrui Hou,
  • Jiarong Chen,
  • Li Tang,
  • Jianrong Zeng,
  • Hongbing Jia,
  • Markus Antonietti,
  • Junwu Zhu

摘要

The structural integrity of layered VOPO4 frameworks critically determines their electrochemical performance in aqueous zinc-ion batteries, yet the highly ordered stacking of VOPO4 renders it susceptible to lattice stress accumulation and chemo-mechanical degradation during cycling, causing rapid capacity fading and a shortened battery lifespan. Herein, we show a strategy to alleviate these limitations through partial metal substitution in the VOPO4 lattice, enabling the modulation of local coordination environments and mitigating lattice and cycling induced stress. As a proof-of-concept, theoretical calculations and experimental validation on Mn-substituted VOPO4 reveal shortened M–O bond along the c-axis and the formation of Mn–O–P–O–V delocalized structure. These modifications introduce subtle lattice distortions and generate percolation channels that enable more facile, ordered Zn2+ migration, facilitating uniform lattice stress distribution. Real-time monitoring of interfacial stress during cycling identifies that Mn incorporation induces electronic redistribution and lattice anisotropy, promoting balanced intra-layer (a/b-axis) stress accommodation. Therefore, Mn-substituted VOPO4 exhibits higher specific capacity and cycling stability, with 91.0% capacity retention over 2000 cycles at 1 A g−1. This intra-layer anisotropy engineering strategy offers a practical route for mitigating dissolution and strain effects during cycling, paving ways for the development of high-energy-density positive electrodes with cycling durability.