PVDF-HFP@Nafion-based quasisolid polymer electrolyte for high migration number in working rechargeable Na-O 2 batteries

• 成果类型: Article
• 署名作者: He, Xin; Ni, Youxuan; Ma, Wenjiao; Zhang, Qiu; Hao, Zhenkun; Hou, Yunpeng; Li, Haixia; Yan, Zhenhua; Zhang, Kai; Chen, Jun
• 署名单位: Nankai University; Hunan University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10254
• DOI: 10.1073/pnas.2320012121
• 发表日期: 2024-06-04
• 关键词: sodium-oxygen batteries; solid-electrolyte; li-o-2 batteries; metal anode; lithium; transport; oxide; host

摘要

Rechargeable sodium - oxygen (Na-O 2 ) battery is deemed as a promising high - energy storage device due to the abundant sodium resources and high theoretical energy density (1,108 Wh kg -1 ). A series of quasisolid electrolytes are constantly being designed to restrain the dendrites growth, the volatile and leaking risks of liquid electrolytes due to the open system of Na-O 2 batteries. However, the ticklish problem about low operating current density for quasisolid electrolytes still hasn't been conquered. Herein, we report a rechargeable Na-O 2 battery with polyvinylidene fluoride - hexafluoropropylene recombination Nafion (PVDF-HFP@Nafion) based quasisolid polymer electrolyte (QPE) and MXene - based Na anode with gradient sodiophilic structure (M - GSS/Na). QPE displays good flame resistance, locking liquid and hydrophobic properties. The introduction of Nafion can lead to a high Na + migration number ( t Na + = 0.68) by blocking the motion of anion and promote the formation of NaF - rich solid electrolyte interphase, resulting in excellent cycling stability at relatively high current density under quasisolid environment. In the meantime, the M - GSS/Na anode exhibits excellent dendrite inhibition ability and cycling stability. Therefore, with the synergistic effect of QPE and M - GSS/Na, constructed Na-O 2 batteries run more stably and exhibit a low potential gap (0.166 V) after an initial 80 cycles at 1,000 mA g -1 and 1,000 mAh g -1 . This work provides the reference basis for building quasisolid state Na-O 2 batteries with long - term cycling stability. Significance The quasi- solid - state electrolyte is an effective strategy for preventing volatile and leaking of liquid organic electrolyte. PVDF-HFP- based electrolytes have attracted extensive attention due to the wide electrochemical window and excellent thermal and electrochemical stabilities. However, PVDF-HFP- based quasi- solid - state electrolytes are seldom applied to Na-O 2 batteries. Besides, compared to liquid electrolytes, the operating current density of quasisolid electrolytes is generally low. Herein, we report a PVDF-HFP@ Nafion- based quasisolid polymer electrolyte, which displays good flame resistance, locking liquid, and hydrophobic properties. The introduction of Nafion can lead to a high t Na + of about 0.68 and promote the formation of NaF- rich solid electrolyte interphase, resulting in excellent cycling stability at relatively high current density in Na-O 2 batteries under the synergistic effect with M- GSS/Na.