Electrochemical cell activated with a nonaqueous electrolyte having a sulfate additive
AssigneeWilson Greatbatch Ltd.
InventorsHong Gan, Esther S. Takeuchi
Life of this patent
Estimating the term…
Abstract
An alkali metal, solid cathode, non-aqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one organic sulfate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, 1,2-dimethoxyethane and a sulfate additive having at least one unsaturated hydrocarbon containing a C(sp or sp2)-C(sp3) bond unit having the C(sp3) carbon directly connected to the —OSO3— functional group.
Claims29
An electrochemical cell, which comprises:
- a) an anode comprising an alkali metal;
- b) a cathode comprising a cathode active material;
- c) a non-aqueous electrolyte operatively associated with the anode and the cathode, the non-aqueous electrolyte comprising a sulfate additive having the general formula R1OS (=O2) (OR2), wherein at least one of R1 and R2 is selected from the group consisting of:
- i) an organic group containing at least 3 carbon atoms and having a structure of the type C(sp)-C(sp3) directly connected to the —OSO3— functional group;
- and
- ii) an unsaturated inorganic group.
A method for reducing voltage delay in a pulse discharging electrochemical cell activated with a nonaqueous electrolyte, comprising the steps of:
- a) providing an anode comprising an alkali metal;
- b) providing a cathode including a mixed metal oxide comprised of vanadium oxide and a second metal “SM” selected from the group consisting of Groups IB, IIB, IIIB, IVB, VIB, VIIB and VIII of the Periodic Table of the Elements, the mixed metal oxide having the general formula SMxV2Oy, wherein 0.30<x<2.0 and 4.5<y<6.0;
- c) activating the electrochemical cell with the non-aqueous electrolyte operatively associated with the anode and the cathode, the non-aqueous electrolyte comprising:
- i) a first solvent selected from the group consisting of an ester, an ether, a dialkyl carbonate, and mixtures thereof;
- ii) a second solvent selected from the group consisting of a cyclic carbonate, a cyclic ester, a cyclic amide, and mixtures thereof;
- iii) a sulfate additive having the general formula R1OS (=O2) (OR2), wherein at least one of R1 and R2 is either an organic group containing at least 3 carbon atoms and having a structure of the type C(sp)-C(sp3) directly connected to the —OSO3— functional group or an unsaturated inorganic group;
- and
- iv) an alkali metal salt dissolved therein;
- and
- d) discharging the cell to deliver at least one current pulse of an electrical current of a greater amplitude than that of a pre-pulse current immediately prior to the pulse.
A method for providing an electrochemical cell, comprising the steps of:
- d) providing an anode comprising an alkali metal;
- e) providing a cathode of a cathode active material;
- f) activating the anode and the cathode with a non-aqueous electrolyte comprising a sulfate additive having the general formula R1OS (=O2) (OR2), wherein at least one of the R1 and R2 is an organic group containing at least 3 carbon atoms and being selected from either a structure of the type C(sp)-C(sp3) directly connected to the —OSO3— functional group or an unsaturated inorganic group.
Dependencies are inferred from the claim text.