Abstract
Iron fluoride, an intercalation-conversion cathode for lithium ion batteries, promises a high theoretical energy density of 1922 Wh kg-1 . However, poor electrochemical reversibility due to repeated breaking/reformation of metal fluoride bonds poses a grand challenge for its practical application. Here we report that both a high reversibility over 1000 cycles and a high capacity of 420 mAh g-1 can be realized by concerted doping of cobalt and oxygen into iron fluoride. In the doped nanorods, an energy density of ∼1000 Wh kg- 1 with a decay rate of 0.03% per cycle is achieved. The anion's and cation's co-substitutions thermodynamically reduce conversion reaction potential and shift the reaction from less-reversible intercalation-conversion reaction in iron fluoride to a highly reversible intercalation-extrusion reaction in doped material. The co-substitution strategy to tune the thermodynamic features of the reactions could be extended to other high energy conversion materials for improved performance.
| Original language | English |
|---|---|
| Article number | 2324 |
| Journal | Nature Communications |
| Volume | 9 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 1 2018 |
Funding
X.F. and C.W. acknowledge the financial support from Army Research Lab under Award Number W911NF1420031. Daikin America provided the high purity fluorinated solvents. The PDF data were collected at XPD beamline (28ID-2) of NSLSII, and the electron microscopy analysis was carried out at the Center for Functional Nanomaterials, Brookhaven National Laboratory (BNL), which is supported by the DOE, Office of Basic EnergySciences, under contract DE-SC0012704. The PDF studies atBNL were supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy through the Advanced Battery Materials Research (BMR) Program, including Battery500 Consortium under contract DE- SC0012704. C.W. and K.X. also acknowledge the support of EERE of USDOE through Battery500 Consortium Seeding project under contract DE-EE0008200. The authors acknowledge the University of Maryland supercomputing resources (http://hpcc.umd. edu) made available for conducting DFT computations in this paper. We also appreciate Dr. Qingping Meng at BNL, and Dr. Nancy J. Dudney at Oak Ridge National Laboratory (ORNL) for the constructive discussions. X.F. and C.W. acknowledge the financial support from Army Research Lab under Award Number W911NF1420031. Daikin America provided the high purity fluorinated solvents. The PDF data were collected at XPD beamline (28ID-2) of NSLSII, and the electron microscopy analysis was carried out at the Center for Functional Nanomaterials, Brookhaven National Laboratory (BNL), which is supported by the DOE, Office of Basic Energy Sciences, under contract DE-SC0012704. The PDF studies at BNL were supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy through the Advanced Battery Materials Research (BMR) Program, including Battery500 Consortium under contract DESC0012704. C.W. and K.X. also acknowledge the support of EERE of USDOE through Battery500 Consortium Seeding project under contract DE-EE0008200. The authors acknowledge the University of Maryland supercomputing resources (http://hpcc.umd. edu) made available for conducting DFT computations in this paper. We also appreciate Dr. Qingping Meng at BNL, and Dr. Nancy J. Dudney at Oak Ridge National Laboratory (ORNL) for the constructive discussions.
