Open AccessRevealing the Fast and Durable Na+ Insertion Reactions in a Layered Na3Fe3(PO4)4 Anode for Aqueous Na-Ion Batteries
Author(s) -
Qing Shen,
Marcos Lucero,
XianYong Wei,
Qi Wang,
Maoyu Wang,
Yan Wang,
Widitha Samarakoon,
Meilani R. Bolding,
Zhenzhen Yang,
Yaqin Huang,
Zhichuan J. Xu,
Meng Gu,
Zhenxing Feng
Publication year - 2021
Publication title -
acs materials au
Language(s) - English
Resource type - Journals
ISSN - 2694-2461
DOI - 10.1021/acsmaterialsau.1c00035
Subject(s) - anode , aqueous solution , materials science , electrolyte , redox , synchrotron , absorption (acoustics) , electrode , ion , absorption spectroscopy , electrochemistry , chemical engineering , inorganic chemistry , analytical chemistry (journal) , chemistry , composite material , metallurgy , organic chemistry , optics , physics , engineering
Aqueous sodium-ion batteries represent a promising approach for stationary energy storage; however, the lack of appropriate anode materials has substantially retarded their development. Herein, we demonstrated an iron-based phosphate material of Na 3 Fe 3 (PO 4 ) 4 as an inexpensive and efficacious anode alternative. While the Fe 3+ /Fe 2+ redox couple renders a two-Na-insertion reaction with desirable potentials, its unique layered structure further facilitates the Na-insertion kinetics and reversibility. Consequently, this electrode exhibits an appealing Na-insertion performance, with a reversible capacity of ∼83 mAh g -1 , suitable anode potential of -0.4 V vs Ag/AgCl, excellent rate capability of 200 C, and outstanding cycling of 6000 cycles. Utilizing operando synchrotron X-ray diffraction and X-ray absorption spectroscopy, we revealed the structural evolution of the Na 3 Fe 3 (PO 4 ) 4 anode during the two-electron reaction, where the extremely small volume expansion (∼3%) enables its fast-charging and long-cycling capability. Our work suggests new considerations of developing versatile iron phosphate compounds as appealing anode materials for energy storage in aqueous electrolytes.