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AssigneeHer Majesty the Queen in right of the Province of British Columbia
InventorsJeffery R. Dahn, Rosamaria Fong, Ulrich Von Sacken
Estimating the term…
Lithiated nickel dioxide cathode-active materials for electrochemical cells aving the formula Li.sub.x Ni.sub.2-x-y M.sub.y O.sub.2, with x being between about 0.8 and about 1.0, M being one or more metals selected from cobalt, iron, chromium, titanium, manganese and vanadium, and y being less than about 0.2, with the proviso that y is less than about 0.5 for cobalt, which material is substantially free of lithium hydroxide and lithium carbonate. The materials are prepared by providing a substantially homogeneous dry intermediate mixture of a starting material containing a nickel compound selected from nickel oxide, nickel hydroxide, and mixtures thereof, and optionally including one or more oxides or hydroxides of a transition metal selected from cobalt, iron, chromium, titanium, manganese and vanadium, together with between about a 10 and about a 25% stoichiometric excess of lithium hydroxide. The mixture is heat treated at a temperature above about 600.degree. C. in an atmosphere substantially free of carbon dioxide and having a partial pressure ratio of oxygen to water vapor greater than about 15, after which any lithium hydroxide or lithium carbonate present in the mixture is removed. Thermally stable lithiated nickel dioxide having a BET surface area less than about 3.0 m.sup.2 /g, and is also disclosed, as well as electrochemical cells prepared from the disclosed lithiated nickel dioxides.
A method of making a lithiated nickel dioxide cathode-active material for an electrochemical cell, having a formula Li.sub.x Ni.sub.2-x-y M.sub.y O.sub.2, wherein x is between about 0.8 and about 1.0, M is one or more metals selected from the group consisting of cobalt, iron, titanium, manganese, chromium and vanadium, and y is less than about 0.2, with the proviso that y is less than about 0.5 for cobalt, which material is substantially free of lithium hydroxide and lithium carbonate, said method comprising the steps of:
A lithiated nickel dioxide cathode-active material for an electrochemical cell, substantially free of lithium hydroxide or lithium carbonate, having a stoichiometric formula Li.sub.x Ni.sub.2-x-y M.sub.y O.sub.2, wherein x is between about 0.80 and about 1.00, M is one or more metals selected from the group consisting of cobalt, iron, chromium, titanium, manganese and vanadium, and y is less than about 0.2, with the proviso that y is less than about 0.5 for cobalt.
A lithiated nickel dioxide cathode-active material for an electrochemical cell having a BET surface area of less than about 3.0 m.sup.2 /g.
An electrochemical cell comprising a cathode containing a cathode-active material having a stoichiometric formula Li.sub.x Ni.sub.2-x-y M.sub.y O.sub.2, wherein x is between about 0.8 and about 1.00, M is one or more metals selected from the group consisting of cobalt, iron, chromium, titanium, manganese and vanadium, and y is less than about 0.2, with the proviso that y is less than about 0.5 for cobalt, an electrolyte, and a counter-electrode capable of intercalating lithium, wherein said cathode-active material is substantially free of lithium hydroxide or lithium carbonate.
An electrochemical cell comprising a cathode containing a cathode-active material comprising lithiated nickel dioxide having a BET surface area less than about 3.0 m.sup.2 /g., an electrolyte, and a counterelectrode capable of intercalating lithium.
Dependencies are inferred from the claim text.