DISORDERED ROCK SALT ELECTRODES FOR LITHIUM BATTERIES
Cation-stabilized materials and compositions are described herein, which suppress the structural and electrochemical instability of lithium-metal-oxide spinel and lithiated lithium-metal-oxide spinel electrodes for lithium batteries, notably lithium-ion batteries. These stabilized materials are attractive as positive electrodes for lithium batteries in their own right or when used as a structural component to stabilize layered metal oxide electrode systems, such as a two-component ‘layered-layered’ system or a multi-component ‘layered-layered-spinel’ system, as defined by the phase diagram and compositional space of each system.
1 . An electrode for a lithium ion electrochemical cell comprising electrochemically active metal oxide particles supported on a metallic current collector, wherein a surface of at least a portion of said particles comprises a cation-stabilized lithium cobalt oxide electrode material of formula: Li 2 (Co 1−x Ni x ) 2−2z M′ 2z O 4 , having a lithiated spinel structure with a rock salt stoichiometry, wherein M′ comprises aluminum, 0≤x≤0.5, and 0<z≤0.5.
2 . The electrode of claim 1 , wherein 0<z≤0.4.
3 . The electrode of claim 1 , wherein 0<z≤0.2.
4 . The electrode of claim 1 , wherein the Li, Co and M′ cations are partially disordered over octahedral and tetrahedral sites of layered and spinel component structures.
5 . The electrode of claim 1 , wherein the material has a structure that is either cation or anion deficient, or both.
6 . The electrode of claim 1 , wherein the cation-stabilized lithium cobalt oxide electrode material is combined with one or more layered or spinel components.
7 . The electrode of claim 1 , wherein the cation-stabilized lithium cobalt oxide electrode material is structurally integrated with one or more layered or spinel components in a composite structure.
8 . The electrode of claim 1 , wherein the cation-stabilized lithium cobalt oxide electrode material is structurally integrated with a two-component layered-layered material of formula: wLi 2 MnO 3 .(1−w)LiMO 2 , wherein M comprises one or more metal cations; and 0<w<1.
9 . The electrode of claim 8 , wherein M comprises one or more cations selected of a metal selected from the group consisting of Ni, Mn, and Co.
10 . The electrode of claim 9 , wherein the Li, Co, Ni, Mn, M and M′ cations are partially disordered over octahedral and tetrahedral sites of layered and spinel component structures.
11 . A lithium metal oxide electrode material for a lithium electrochemical cell comprising a disordered rock salt structure with partial lithiated-spinel character, wherein the disordered rock salt structure comprises a formula Li 2 (M″ 2−a M′″ a )O 4 , which has the crystallographic formula: [Li 2−b M′″ b ] 16c [M″ 2−a M′″ a−b Li b ] 16d O 4 wherein 16c and 16d refer to the octahedral sites of the prototypic space group symmetry Fd 3 m; M″ and M′″ are metal ions; 0<a≤0.5; and 0<b<0.5.
12 . The electrode material of claim 11 , wherein M″ comprises one or more metals selected from the group consisting of Co, Ni, Mn, V and Fe; M′″ is one or more metals selected from the group consisting of Al, Ga, Mg and Ti.
13 . The electrode material of claim 11 , wherein the material has a structure that is either cation or anion deficient, or both.
14 . The electrode material of claim 11 , wherein the Li, M″ and M′″ cations are partially disordered over octahedral and tetrahedral sites of layered and spinel component structures.
15 . The electrode material of claim 11 , wherein the cation-stabilized lithium cobalt oxide electrode material is structurally integrated with a two-component layered-layered material of formula: wLi 2 MnO 3 .(1−w)LiMO 2 , wherein M comprises one or more metal cations; and 0<w<1.
16 . The electrode material of claim 15 , wherein M comprises one or more cations selected from the group consisting of Ni, Mn, and Co.
17 . The electrode material of claim 16 , wherein the Li, Co, Ni, Mn, M″ and M′″ cations are partially disordered over octahedral and tetrahedral sites of layered and spinel component structures.
18 . The electrode material of claim 11 , wherein 0<a−b<0.2.
19 . The electrode material of claim 11 , wherein 0<a<0.3 and 0<a−b<0.1.
20 . The electrode material of claim 11 , wherein 0<a−b<0.05.
21 . An electrode comprising the electrode material of claim 11 supported on a metallic current collector.
22 . An electrochemical cell comprising an anode, a cathode, and a lithium-containing electrolyte contacting the anode and cathode, wherein one or more of the anode and the cathode is the electrode of claim 21 .
23 . A battery comprising a plurality of electrochemical cells of claim 22 , electrically connected in series, in parallel, or in both series and parallel.
24 . An electrochemical cell comprising an anode, a cathode, and a lithium-containing electrolyte contacting the anode and cathode, wherein one or more of the anode and the cathode is the electrode of claim 1 .
25 . A battery comprising a plurality of electrochemical cells of claim 24 , electrically connected in series, in parallel, or in both series and parallel.