Abstract
The aqueous sodium-ion battery system is a safe and low-cost solution for large-scale energy storage, because of the abundance of sodium and inexpensive aqueous electrolytes. Although several positive electrode materials, for example, Na0.44 MnO2, were proposed, few negative electrode materials, for example, activated carbon and NaTi2 (PO4)3, are available. Here we show that Ti-substituted Na0.44MnO2 (Na0.44[Mn1-xTix]O2) with tunnel structure can be used as a negative electrode material for aqueous sodium-ion batteries. This material exhibits superior cyclability even without the special treatment of oxygen removal from the aqueous solution. Atomic-scale characterizations based on spherical aberration-corrected electron microscopy and ab initio calculations are utilized to accurately identify the Ti substitution sites and sodium storage mechanism. Ti substitution tunes the charge ordering property and reaction pathway, significantly smoothing the discharge/charge profiles and lowering the storage voltage. Both the fundamental understanding and practical demonstrations suggest that Na0.44[Mn1-xTix]O2 is a promising negative electrode material for aqueous sodium-ion batteries.
| Original language | English |
|---|---|
| Article number | 6401 |
| Journal | Nature Communications |
| Volume | 6 |
| DOIs | |
| State | Published - Mar 2015 |
| Externally published | Yes |
Funding
This work was supported by funding from the NSFC (51222210, 11234013), ‘973’ Projects (2012CB932900) and the One Hundred Talent Project of the Chinese Academy of Sciences. The work at Brookhaven National Laboratory was supported by the US Department of Energy, the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies under Contract Number DEAC02-98CH10886 and DE-SC0012704. We acknowledge the support by the scientists at beamline X14A and X18A at NSLS (BNL) and beamline 8.0.1 at ALS(LBNL). We thank the BASF company for providing the non-aqueous electrolyte solvents used in this work.
