Boosting the sodium storage performance of Prussian blue analogues via effective etching
Publication Name
Science China Chemistry
Abstract
Prussian blue analogues (PBAs) have gained significant popularity as cathode materials for sodium-ion batteries (SIBs) due to their remarkable features such as high capacity and convenient synthesis. However, PBAs usually suffer from kinetic problems during the electrochemical reactions due to sluggish Na+ diffusion in the large crystals, resulting in low-capacity utilization and inferior rate capability. In this study, we present a facile etching method aiming at activating the sodium storage sites and accelerating the Na+ transport of Na2NiFe(CN)6 (denoted as NaNiHCF) by precisely controlling its morphologies. A progressive corner passivation phenomenon occurred in NaNiHCF during the etching process, which led to a substantial augmentation of the specific surface area as the morphology transitioned from a standard cube to a dice shape. Notably, by controlling the etching time, the obtained NaNiHCF-3 electrode exhibited boosted electrochemical performance with high reversible capacity of 83.5 mAh g−1 (98.2% of its theoretical capacity), superior rate capability (71.2 mAh g−1 at 10 C), and stable cycling life-span at different temperatures. Both experimental and computational methods reveal the remarkably reversible structural evolution process and improved Na+ diffusion coefficient. We believe that this work can serve as an indispensable reference to tailor the structure of PBAs to obtain improved electrochemical performance.[Figure not available: see fulltext.]
Open Access Status
This publication is not available as open access
Volume
66
Issue
11
First Page
3154
Last Page
3160
Funding Number
21972108
Funding Sponsor
National Natural Science Foundation of China