<p>Ion migration capability and interfacial chemistry of solid polymer electrolytes (SPEs) in all-solid-state sodium metal batteries (ASSMBs) are closely related to the Na<sup>+</sup> coordination environment. Herein, an electrostatic engineering strategy is proposed to regulate the Na<sup>+</sup> coordinated structure by employing a fluorinated metal–organic framework as an electron-rich model. Theoretical and experimental results revealed that the abundant electron-rich F sites can accelerate the disassociation of Na-salt through electrostatic attraction to release free Na<sup>+</sup>, while forcing anions into a Na<sup>+</sup> coordination structure though electrostatic repulsion to weaken the Na<sup>+</sup> coordination with polymer, thus promoting rapid Na<sup>+</sup> transport. The optimized anion-rich weak solvation structure fosters a stable inorganic-dominated solid–electrolyte interphase, significantly enhancing the interfacial stability toward Na anode. Consequently, the Na/Na symmetric cell delivered stable Na plating/stripping over 2500&#xa0;h at 0.1&#xa0;mA&#xa0;cm<sup>−2</sup>. Impressively, the assembled ASSMBs demonstrated stable performance of over 2000 cycles even under high rate of 2&#xa0;&#xa0;C with capacity retention nearly 100%, surpassing most reported ASSMBs using various solid-state electrolytes. This work provides a new avenue for regulating the Na<sup>+</sup> coordination structure of SPEs by exploration of electrostatic effect engineering to achieve high-performance all-solid-state alkali metal batteries.</p> Graphical Abstract <p></p>

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Electrostatic Regulation of Na+ Coordination Chemistry for High-Performance All-Solid-State Sodium Batteries

  • Penghui Song,
  • Suli Chen,
  • Junhong Guo,
  • Junchen Wu,
  • Qiongqiong Lu,
  • Haijiao Xie,
  • Qingsong Wang,
  • Tianxi Liu

摘要

Ion migration capability and interfacial chemistry of solid polymer electrolytes (SPEs) in all-solid-state sodium metal batteries (ASSMBs) are closely related to the Na+ coordination environment. Herein, an electrostatic engineering strategy is proposed to regulate the Na+ coordinated structure by employing a fluorinated metal–organic framework as an electron-rich model. Theoretical and experimental results revealed that the abundant electron-rich F sites can accelerate the disassociation of Na-salt through electrostatic attraction to release free Na+, while forcing anions into a Na+ coordination structure though electrostatic repulsion to weaken the Na+ coordination with polymer, thus promoting rapid Na+ transport. The optimized anion-rich weak solvation structure fosters a stable inorganic-dominated solid–electrolyte interphase, significantly enhancing the interfacial stability toward Na anode. Consequently, the Na/Na symmetric cell delivered stable Na plating/stripping over 2500 h at 0.1 mA cm−2. Impressively, the assembled ASSMBs demonstrated stable performance of over 2000 cycles even under high rate of 2  C with capacity retention nearly 100%, surpassing most reported ASSMBs using various solid-state electrolytes. This work provides a new avenue for regulating the Na+ coordination structure of SPEs by exploration of electrostatic effect engineering to achieve high-performance all-solid-state alkali metal batteries.

Graphical Abstract