Shunt current elimination
AssigneeExxon Research & Engineering Co.
InventorsPatrick G. Grimes, Markus Zahn, Richard J. Bellows
Life of this patent
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Abstract
Shunt currents can be eliminated in electrochemical devices by introducing nulling currents via auxiliary electrodes. The invention teaches the reduction or elimination of these shunt currents in such devices with minimized power consumption. Shunt current nulling tunnels are provided which interconnect with electrolyte supply channels feeding the cells of the electrochemical device. Power consumption for the shunt current-nulling tunnels is reduced by designing the tunnels to have an increasing electrical resistance towards their mid-portions. Another embodiment of the invention features an increasing electrical resistance towards the mid-portion of the tunnels and a decreasing electrical resistance towards the mid-portion of the manifolds.
Claims33
An electrochemical device, comprising:
- at least one common manifold;
- a plurality of cells fluidically communicating through corresponding channels with said one common manifold, said manifold and channels adapted to contain a common electrolyte for said cells, said electrolyte providing an electrical electrolytic conductive bypass path around said cells which is capable of resulting in undesirable shunt currents;
- at least one tunnel intersecting and connecting with each of said corresponding channels, said tunnel having a given electrical resistance as between said corresponding channels which increases towards a mid-portion of said tunnel, for substantially eliminating any voltage difference between each of said cells and their corresponding tunnel and channel intersections when a protective current is passed into said tunnel for providing effective reduction of said shunt currents;
- and
- means for passing a protective current into said one tunnel.
An electrochemical device, comprising:
- at least one common manifold having a given electrical resistance along said manifold which decreases towards a mid-portion thereof;
- a plurality of cells fluidically communicating through corresponding channels with said one common manifold, said manifold and channels adapted to contain a common electrolyte for said cells, said electrolyte providing an electrical electrolytic conductive bypass path around said cells which is capable of resulting in undesirable shunt currents;
- at least one tunnel intersecting and connecting with each of said corresponding channels, said tunnel having a given electrical resistance as between said corresponding channels which increases towards a mid-portion of said tunnel, for substantially eliminating any voltage difference between each of said cells and their corresponding tunnel and channel intersections when a protective current is passed into said tunnel for providing effective reduction of said shunt currents;
- and
- means for passing a protective current into said one tunnel.
Dependencies are inferred from the claim text.