Cation-disordered oxides for rechargeable lithium batteries and other applications
Embodiments related to cation-disordered lithium metal oxide compounds, their methods of manufacture, and use are described. In one embodiment, a cation-disordered lithium metal oxide includes Li a M b M′ c O 2 with a greater than 1. M includes at least one redox-active species with a first oxidation state n and an oxidation state n′ greater than n, and M is chosen such that a lithium-M oxide having a formula LiMO 2 forms a cation-disordered rocksalt structure. M′ includes at least one charge-compensating species that has an oxidation state y that is greater than n.
1. A lithium metal oxide having a general formula: Li a M b M′ c O 2 , said lithium metal oxide comprising LiMO 2 and Li a M′ e O 2 , said lithium metal oxide having a cation-disordered rocksalt structure, wherein M comprises one or more of a metallic species chosen from a group consisting of Ti, V, Cr, Ni, Co, Fe, Mn, Zr, Sb, and Mo, M being chosen such that LiMO 2 forms a cation-disordered rocksalt structure, and M having a first average oxidation degree n, wherein M′ comprises one or more of a metallic species chosen from a group consisting of Ti, Cr, Mn, Zr, Mo, Sn, Sb, and W, and M′ having a second average oxidation degree y greater than or equal to n, with 4<=y<=6, and wherein 1<a<=1.4, a+b+c=2, d+e=2, d+(e·y)=4, a+(b·n)+(c·y)=4,1.3<=d<=1.7,and 0.2<=b<1.
2. The lithium metal oxide of claim 1 , wherein said disordered LiMO 2 rocksalt structure is enriched with Li a M′ e O 2 .
3. The lithium metal oxide of claim 1 , comprising Li 1+x/100 (NiTi) 1/2−x/120 Mo x/150 O 2 , and wherein 0<x<=30.
4. The lithium metal oxide of claim 3 , wherein x is 20.
5. The lithium metal oxide of claim 1 , wherein n is between 2.7 and 3.3.
6. The lithium metal oxide of claim 1 , wherein M′ is one or more of a metallic species chosen from a group consisting of Mo and Cr, and wherein b=(8−5a)/3, c=[2(a−1)]/3, d=1.6, and e=0.4.
7. The lithium metal oxide of claim 1 , wherein M is an alloy of Ni and Ti in a 1:1 molar ratio and/or M′ is Mo and y is equal to 6.
8. The lithium metal oxide of claim 1 , wherein XRD of the lithium metal oxide collected using Cu Kα radiation shows, in a range 5-70 degrees of 2θ (2 theta), a series of normalized intensity ratios I′z, with I′z=Iz/I(111), Iz being a first intensity of a (z) peak and I(111) being a second intensity of a (111) peak, wherein when z refers to a (111) peak, I′z=1, when z refers to a (022) peak, 2<I′z<5, and when z refers to a (002) peak, 4<I′z<10, wherein said series of normalized intensity ratios I′z corresponds to a disordered rocksalt LiMO 2 structure having a Fm-3m space group.
9. The lithium metal oxide of claim 1 , wherein the lithium metal oxide has a lattice parameter greater than or equal to 4 Angstroms.
10. The lithium metal oxide of claim 1 , wherein the lithium metal oxide has a first capacity greater than 109 mAh/g when charged and discharged between 1.5 and 4.5V at 20 mA/g at room temperature.
11. The lithium metal oxide of claim 1 , wherein the lithium metal oxide presents a single phase cation-disordered rocksalt structure.
12. An electrical device, comprising an electrode comprising the lithium metal oxide of claim 1 .
13. The lithium metal oxide of claim 1 , wherein n is 3.
14. The lithium metal oxide of claim 1 , wherein the lithium metal oxide has a lattice parameter between 4.13 Angstroms and 4.15 Angstroms.
15. The lithium metal oxide of claim 1 , wherein the lithium metal oxide has a first capacity greater than 150 mAh/g when charged and discharged between 1.5 and 4.5V at 20 mA/g at room temperature.
16. The lithium metal oxide of claim 15 , wherein the first discharge capacity is at least 200 mAh/g.
17. The lithium metal oxide of claim 1 , wherein y is at least 5.
18. The lithium metal oxide of claim 1 , wherein M includes at least Ni and Ti.
19. The lithium metal oxide of claim 1 , wherein the lithium metal oxide has not been subjected to a charge and/or discharge cycle.