Mass-Producible, Quasi-Zero-Strain, Lattice-Water-Rich Inorganic Open-Frameworks for Ultrafast-Charging and Long-Cycling Zinc-Ion Batteries.

Yang, Xin; Deng, Wenzhuo; Chen, Ming; Wang, Yaobing; Sun, Chuan-Fu · Adv Mater · 2020

basic_science · Level V

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Abstract

Low-cost and high-safety aqueous Zn-ion batteries are an exceptionally compelling technology for grid-scale energy storage. However, their development has been plagued by the lack of stable cathode materials allowing fast Zn<sup>2+</sup> -ion insertion and scalable synthesis. Here, a lattice-water-rich, inorganic-open-framework (IOF) phosphovanadate cathode, which is mass-producible and delivers high capacity (228 mAh g<sup>-1</sup> ) and energy density (193.8 Wh kg<sup>-1</sup> or 513 Wh L<sup>-1</sup> ), is reported. The abundant lattice waters functioning as a "charge shield" enable a low Zn<sup>2+</sup> -migration energy barrier, (0.66 eV) even close to that of Li<sup>+</sup> within LiFePO<sub>4</sub> . This fast intrinsic ion-diffusion kinetics, together with nanostructure effect, allow the achievements of ultrafast charging (71% state of charge in 1.9 min) and an ultrahigh power density (7200 W kg<sup>-1</sup> at 107 Wh kg<sup>-1</sup> ). Equally important, the IOF exhibits a quasi-zero-strain feature (<1% lattice change upon (de)zincation), which ensures ultrahigh cycling durability (3000 cycles) and Coulombic efficiencies of 100%. The cell-level energy and power densities reach ≈90 Wh kg<sup>-1</sup> and ≈3320 W kg<sup>-1</sup> , far surpassing commercial lead-acid, Ni-Cd, and Ni-MH batteries. Lattice-water-rich IOFs may open up new opportunities for exploring stable and fast-charging Zn-ion batteries.