Uchicago Argonne, LLC

Joong Sun Park

Jason R Croy

Michael M Thackeray

Jeffrey W Elam

Anil U Mane

Eungje Lee

Brandon R Long

Khalil Amine

Mahalingam Balasubramanian

Bryan T Yonemoto

The fabrication of robust interfaces between transition metal oxides and non-aqueous electrolytes is one of the great challenges of lithium ion batteries. Atomic layer deposition (ALD) of aluminum tungsten fluoride (AlWF) improves the electrochemical stability of LiCoO. AlWFthin films were deposited by combining trimethylaluminum and tungsten hexafluoride. in-situ quartz crystal microbalance and transmission electron microscopy studies show that the films grow in a layer-by-layer fashion and are amorphous nature. Ultrathin AlWFcoatings (<10 Å) on LiCoOsignificantly enhance stability relative to bare LiCoOwhen cycled to 4.4 V. The coated LiCoO2 exhibited superior rate capability (up to 400 mA/g) and discharge capacities at a current of 400 mA/g were 51% and 92% of the first cycle capacities for the bare and AlWFcoated materials. These results open new possibilities for designing ultrathin and electrochemically robust coatings of metal fluorides via ALD to enhance the stability of Li-ion electrodes.

Metal fluoride passivation coatings prepared by atomic layer deposition for Li-ion batteries

The fabrication of robust interfaces between transition metal oxides and non-aqueous electrolytes is one of the great challenges of lithium ion batteries. Atomic layer deposition (ALD) of aluminum tungsten fluoride (AlWF) improves the electrochemical stability of LiCoO. AlWFthin films were deposited by combining trimethylaluminum and tungsten hexafluoride. in-situ quartz crystal microbalance and transmission electron microscopy studies show that the films grow in a layer-by-layer fashion and are amorphous nature. Ultrathin AlWFcoatings (&#x3c;10 &#x212b;) on LiCoOsignificantly enhance stability relative to bare LiCoOwhen cycled to 4.4 V. The coated LiCoOexhibited superior rate capability (up to 400 mA/g) and discharge capacities at a current of 400 mA/g were 51% and 92% of the first cycle capacities for the bare and AlWFcoated materials. These results open new possibilities for designing ultrathin and electrochemically robust coatings of metal fluorides via ALD to enhance the stability of Li-ion electrodes.

An electrode material comprising a composite lithium metal oxide, which in an initial state has the formula: y[xLiMO.(1&#x2212;x)LiM'O].(1&#x2212;y)LiMnM&#x2033;O; wherein 0&#x2264;x&#x2264;1; 0.75&#x2264;y&#x3c;1; 0&#x3c;z&#x2264;2; 0&#x2264;d&#x2264;0.2; and z&#x2212;d&#x2264;2. M comprises one or more metal ions that together have an average oxidation state of +4; M&#x2032; comprises one or more metal ions that together have an average oxidation state of +3; and M&#x2033; comprises one or more metal ions that together with the Mn and any excess proportion of lithium, 'd', have a combined average oxidation state between +3.5 and +4. The LiMnM&#x2033;Ocomponent comprises a spinel structure, each of the LiMOand the LiM&#x2032;Ocomponents comprise layered structures, and at least one of M, M&#x2032;, and M&#x2033; comprises Co. Cells and batteries comprising the electrode material also are described.

Cobalt-stabilized lithium metal oxide electrodes for lithium batteries

An electrode for a lithium-ion cell comprising a 'layered-spinel' composite oxide material is disclosed. The 'layered-spinel' can be a material of formula xLiMO.(1&#x2212;x)LiM'O, wherein 0&#x3c;x&#x3c;1; LiMOis a lithium metal oxide having a layered structure in which M comprises one or more transition metals and optionally lithium, and has a combined average oxidation state of +3; and LiM&#x2032;Ois a lithium metal oxide having a spinel structure, 1&#x2264;y&#x2264;1.33, 1.66&#x2264;z&#x2264;2, and M&#x2032; comprises one or more transition metals, and has a combined average metal oxidation state in the range of about +3.5 to about +4.

Layered-spinel electrodes for lithium batteries

The surface of a lithium ion cathode material (e.g., a lithium metal oxide material capable of releasing and accepting lithium ions during charging and discharging, respectively, of a lithium ion electrochemical cell) is coated with a lithium metal oxide (LMO) material comprising a high-valent metal to, inter alia, reduce interfacial resistance toward lithium exchange. Li-rich phases on the surface of the treated LMO particles allow for better lithium ion diffusion. The inclusion of elements that form phases with lithium and can substitute in the host structure allow for mixing across interfaces leading to more robust structures that better mimic epitaxial-type layers. Inclusion of doping elements in place of some of the high-valent metal in the surface-treating composition provides unexpectedly improved performance over surface treatments comprising lithium metal oxides that only include a high-valent metal.

High valent lithiated surface structures for lithium ion battery electrode materials

A structurally inhomogeneous lithium metal oxide material having the Formula (I): y[xLiMO&#x2022;(1-x)LiM'O]&#x2022;(1-y)LiM&#x2033;O; wherein 0&#x2264;x&#x2264;1; 0&#x3c;y&#x3c;1; 0&#x2264;d&#x2264;0.33; and wherein the LiM&#x2033;Ocomponent comprises a spinel structure, and each of the LiMOand the LiM&#x2032;components thereof comprise layered structures. Each of M, M&#x2032;, and M&#x2033; independently comprises one or more metal ions. The composition of the material of Formula (I) varies across the electrode particles by changing at least one of x, y, d, M, M&#x2032; and M&#x2033;. Electrodes, cells and batteries comprising the lithium metal oxide material are also described.

Stabilized electrodes for lithium batteries

The fabrication of robust interfaces between transition metal oxides and non-aqueous electrolytes is one of the great challenges of lithium ion batteries. Atomic layer deposition (ALD) of aluminum tungsten fluoride (AlWF) improves the electrochemical stability of LiCoO. AlWFthin films were deposited by combining trimethylaluminum and tungsten hexafluoride. in-situ quartz crystal microbalance and transmission electron microscopy studies show that the films grow in a layer-by-layer fashion and are amorphous nature. Ultrathin AlWFcoatings (&#x3c;10 &#x212b;) on LiCoOsignificantly enhance stability relative to bare LiCoOwhen cycled to 4.4 V. The coated LiCoO2 exhibited superior rate capability (up to 400 mA/g) and discharge capacities at a current of 400 mA/g were 51% and 92% of the first cycle capacities for the bare and AlWFcoated materials. These results open new possibilities for designing ultrathin and electrochemically robust coatings of metal fluorides via ALD to enhance the stability of Li-ion electrodes.

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Woodridge, IL, United States of America

Joong Sun Park