Aqueous electrolyte energy storage device
An electrochemical device including a housing and a stack of electrochemical cells in the housing. Each electrochemical cell includes an anode electrode, a cathode electrode, a separator located between the anode electrode and the cathode electrode and an electrolyte. The electrochemical device also includes a current collector located between adjacent electrochemical cells, an anode bus operatively connected to the anodes of the electrochemical cells in the stack and a cathode bus operatively connected to the cathodes of the electrochemical cells in the stack. The housing, the anode electrode, the cathode electrode, the separator, the anode bus and the cathode bus are non-metallic.
1. An electrochemical device comprising:
a housing;
a stack of electrochemical cells in the housing, each electrochemical cell comprising:
an anode electrode;
a cathode electrode;
a separator located between the anode electrode and the cathode electrode; and
an electrolyte;
a current collector located between adjacent electrochemical cells;
an anode bus operatively connected to the anodes of the electrochemical cells in the stack; and
a cathode bus operatively connected to the cathodes of the electrochemical cells in the stack,
wherein, the anode electrode, the anode bus and the cathode bus comprise graphite
wherein the cathode electrode comprises a doped or undoped cubic spinel -MnO 2 -type material or NaMn 9 O 18 tunnel structured orthorhombic material, the anode electrode comprises activated carbon and the electrolyte comprises sodium ions;
wherein the electrochemical cells in the stack of electrochemical cells are stacked in a prismatic configuration, wherein:
the anode electrode of each electrochemical cell in the prismatic stack is electrically connected to the anode bus;
the anode electrodes of the electrochemical cells in the prismatic stack are electrically connected in parallel to the anode bus;
the anode bus is electrically connected to a positive contact which protrudes outside the housing;
the cathode electrode of each electrochemical cell in the prismatic stack is electrically connected to the cathode bus; and
the cathode electrodes of the electrochemical cells in the prismatic stack are electrically connected in parallel to the cathode bus; and
the cathode bus is electrically connected to a negative contact which protrudes outside the housing.
2. The electrochemical device of claim 1 , wherein the current collector comprises graphite.
3. The electrochemical device of claim 2 , wherein the density of the graphite is greater than 0.6 g/cm 3 .
4. The electrochemical device of claim 1 , wherein the electrochemical device is a hybrid aqueous electrolyte energy storage device where the electrolyte is not in contact with a metallic material.
5. The electrochemical device of claim 4 , wherein the cathode comprises an alkali ion intercalation material and the anode is a pseudocapacitive or electrochemical double layer capacitive material that is electrochemically stable to less than −1.3 V vs. NHE.
6. The electrochemical device of claim 5 , wherein the anode electrode comprises carbon nanotube.
7. The electrochemical device of claim 4 , wherein the electrolyte is an aqueous solution containing dissolved alkali ions that are able to interact with both anode and cathode such that charge may be stored via intercalation at the cathode electrode and by pseudocapacitive non-faradic surface reaction at the anode electrode.
8. The electrochemical device of claim 1 , wherein the anode bus and the cathode bus comprise graphite; and the housing comprises an electrochemically inert polymer.
9. The electrochemical device of claim 1 wherein the cathode current collectors are operatively and electrically connected to the cathode bus by cathode side carbon tabs, the anode current collectors are operatively and electrically connected to the anode bus by anode side carbon tabs.
10. The electrochemical device of claim 9 , wherein the current collectors are operatively connected to the anode and cathode buses with a pressure/friction fitting, a conducting, electrochemically inert cured paint, or a conducting, electrochemically inert cured epoxy.
11. The electrochemical device of claim 1 , wherein the housing is hermetically sealed.
12. The electrochemical device of claim 1 , further comprising metallic contacts which protrude outside of the housing and electrically connected to the anode bus and the cathode bus; and a hermetic seal which coats a junction of the bus bars with a respective contact.
13. The electrochemical device of claim 1 , wherein
the anode electrode comprises a plurality of discrete anode electrode members separated by anode boundary areas; and
the cathode electrode comprises a plurality of discrete cathode electrode members separated by cathode boundary areas.
14. The electrochemical device of claim 2 , wherein the current collector comprises densified, exfoliated graphite.