Abstract
Layered LixMnyO2 materials with the O3 (α-NaFeO2) structure have been synthesised by a low temperature ion exchange route from the corresponding sodium compounds. Previous studies have concentrated upon the undoped and singly doped families of O3 layered lithium manganese oxides. This is the first report of multiply doped analogues. The effects on electrochemical performance (ability to store reversibly large quantities of lithium and hence charge) and crystal chemistry of partially substituting some of the Mn ions with two dopants have been investigated. A range of structural (X-ray and neutron diffraction) and electrochemical (galvanostatic cycling and a.c. impedance) techniques as well as chemical analyses were utilised. The new materials, LixMn y-2zMzM′zO2 (M, M′ = Li, Cu, Mg, Ni, Zn, Al and Co), offer high capacities in excess of 200 mA h g -1 at a rate of 50 mA g-1 (C/4) with the highest values being for the z = 0.025 series. The main advantage of the multiply doped materials over the previously reported undoped and singly doped O3 layered lithium manganese oxides is their far superior rate capability. All the compounds in this study irreversibly transform to spinel-like materials on extended cycling. This is not, however, detrimental to their electrochemical performance and is analogous to the behaviour of other lightly doped O3 layered lithium manganese oxides.
| Original language | English |
|---|---|
| Pages (from-to) | 2367-2373 |
| Number of pages | 7 |
| Journal | Journal of Materials Chemistry |
| Volume | 13 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 1 Sep 2003 |
| Externally published | Yes |
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Nonstoichiometric layered LixMnyO2 intercalation electrodes : a multiple dopant strategy. / Robertson, Alastair D.; Armstrong, A. Robert; Paterson, Allan J.; Duncan, Morven J.; Bruce, Peter G.
In: Journal of Materials Chemistry, Vol. 13, No. 9, 01.09.2003, p. 2367-2373.Research output: Contribution to journal › Article
TY - JOUR
T1 - Nonstoichiometric layered LixMnyO2 intercalation electrodes
T2 - a multiple dopant strategy
AU - Robertson, Alastair D.
AU - Armstrong, A. Robert
AU - Paterson, Allan J.
AU - Duncan, Morven J.
AU - Bruce, Peter G.
PY - 2003/9/1
Y1 - 2003/9/1
N2 - Layered LixMnyO2 materials with the O3 (α-NaFeO2) structure have been synthesised by a low temperature ion exchange route from the corresponding sodium compounds. Previous studies have concentrated upon the undoped and singly doped families of O3 layered lithium manganese oxides. This is the first report of multiply doped analogues. The effects on electrochemical performance (ability to store reversibly large quantities of lithium and hence charge) and crystal chemistry of partially substituting some of the Mn ions with two dopants have been investigated. A range of structural (X-ray and neutron diffraction) and electrochemical (galvanostatic cycling and a.c. impedance) techniques as well as chemical analyses were utilised. The new materials, LixMn y-2zMzM′zO2 (M, M′ = Li, Cu, Mg, Ni, Zn, Al and Co), offer high capacities in excess of 200 mA h g -1 at a rate of 50 mA g-1 (C/4) with the highest values being for the z = 0.025 series. The main advantage of the multiply doped materials over the previously reported undoped and singly doped O3 layered lithium manganese oxides is their far superior rate capability. All the compounds in this study irreversibly transform to spinel-like materials on extended cycling. This is not, however, detrimental to their electrochemical performance and is analogous to the behaviour of other lightly doped O3 layered lithium manganese oxides.
AB - Layered LixMnyO2 materials with the O3 (α-NaFeO2) structure have been synthesised by a low temperature ion exchange route from the corresponding sodium compounds. Previous studies have concentrated upon the undoped and singly doped families of O3 layered lithium manganese oxides. This is the first report of multiply doped analogues. The effects on electrochemical performance (ability to store reversibly large quantities of lithium and hence charge) and crystal chemistry of partially substituting some of the Mn ions with two dopants have been investigated. A range of structural (X-ray and neutron diffraction) and electrochemical (galvanostatic cycling and a.c. impedance) techniques as well as chemical analyses were utilised. The new materials, LixMn y-2zMzM′zO2 (M, M′ = Li, Cu, Mg, Ni, Zn, Al and Co), offer high capacities in excess of 200 mA h g -1 at a rate of 50 mA g-1 (C/4) with the highest values being for the z = 0.025 series. The main advantage of the multiply doped materials over the previously reported undoped and singly doped O3 layered lithium manganese oxides is their far superior rate capability. All the compounds in this study irreversibly transform to spinel-like materials on extended cycling. This is not, however, detrimental to their electrochemical performance and is analogous to the behaviour of other lightly doped O3 layered lithium manganese oxides.
U2 - 10.1039/b302245e
DO - 10.1039/b302245e
M3 - Article
AN - SCOPUS:0042261730
VL - 13
SP - 2367
EP - 2373
JO - Journal of Materials Chemistry
JF - Journal of Materials Chemistry
SN - 0959-9428
IS - 9
ER -