Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
209 words
An electrochemical cell, comprising, an external cell housing which is closed in relation to a surrounding atmosphere, electrodes located within the cell housing in contact with a liquid electrolyte, at least one of the electrodes being a gas diffusion electrode, an external surface of the gas diffusion electrode being provided with both a catalyst for converting gas to electricity and an electrically conductive material, an internal surface of the gas diffusion electrode being provided with a hydrophobic material, the hydrophobic material of the gas diffusion electrode including a cohesive porous plastics layer having pores which are impermeable to liquid but permeable to gas, a gas space totally sealed about its periphery being defined inside the electrode, said gas diffusion electrode permitting gas to diffuse to and from said gas space and preventing entry of water or electrolyte into the gas space the gas diffusion electrode being partially immersed in the electrolyte and having a portion of the electrode in contact with gas in a gas chamber located within the cell housing above the electrolyte, the gas diffusion electrode being adapted for drawing gas from the gas chamber through the gas permeable pores into the gas space by a subpressure generated within the gas space during operation of the cell.
Claim 2
Dependent Claim
209 words
An electrochemical cell, comprising, an external cell housing which is closed in relation to a surrounding atmosphere, electrodes located within the cell housing in contact with a liquid electrolyte, at least one of the electrodes being a gas diffusion electrode, an external surface of the gas diffusion electrode being provided with both a catalyst for converting gas to electricity and an electrically conductive material, an internal surface of the gas diffusion electrode being provided with a hydrophobic material, the hydrophobic material of the gas diffusion electrode including a cohesive porous plastics layer having pores which are impermeable to liquid but permeable to gas, a gas space totally sealed about its periphery being defined inside the electrode, said gas diffusion electrode permitting gas to diffuse to and from said gas space and preventing entry of water or electrolyte into the gas space the gas diffusion electrode being partially immersed in the electrolyte and having a portion of the electrode in contact with gas in a gas chamber located within the cell housing above the electrolyte, the gas diffusion electrode being adapted for drawing gas from the gas chamber through the gas permeable pores into the gas space by a subpressure generated within the gas space during operation of the cell.
Claim 3
Dependent Claim
38 words
An electrochemical cell as claimed in claim 1, wherein the sealed gas space is formed as a pocket with walls in the form of sheets of the hydrophobic, porous plastic material, the walls being separated by spacer elements.
Claim 4
Dependent Claim
32 words
An electrochemical cell as claimed in claim 1, wherein the sealed gas space is formed by a porous body which is coated on an exterior surface with the hydrophobic porous plastics material.
Claim 5
Dependent Claim
25 words
An electrochemical cell as claimed in claim 3, wherein the porous body has greater sized pores than the pores in the exterior porous plastics material.
Claim 6
Dependent Claim
38 words
An electrochemical cell as claimed in any one of the preceding claims, wherein the gas diffusion electrode has increasing hydrophobicity towards an end which is immersed in the electrolyte to compensate for the hydrostatic pressure of the electrolyte.
Claim 7
Dependent Claim
31 words
An electrochemical cell as claimed in claim 1, wherein the portion of the gas diffusion electrode above the electrolyte constitutes at least 1% of the total surface area of the electrode.
Claim 8
Dependent Claim
35 words
An electrochemical cell as claimed in claim 6, wherein the surface area of the gas diffusion electrode above the electrolyte level is within the range of 1-15% of the total surface area of the electrode.
Claim 9
Dependent Claim
30 words
An electrochemical cell as claimed in claim 1, wherein the gas diffusion electrode is provided with a catalyst only on external surface portions which are disposed under the electrolyte surface.
Claim 10
Dependent Claim
24 words
An electrochemical cell as claimed in claim 1, wherein said cell housing contains a hydrogen-oxygen catalyst in contact with the gas above the electrolyte.
Claim 11
Dependent Claim
93 words
A gas diffusion electrode for an electrochemical cell, comprising, an external surface provided with both a catalyst for converting gas to electricity and an electrically conductive material, an internal surface being provided with a hydrophobic material, the hydrophobic material being a cohesive porous plastics layer having pores impermeable to liquid and permeable to gas, a gas space totally sealed about its periphery being defined inside the electrode, said gas diffusion electrode permitting gas to diffuse from and to said sealed gas space and preventing entry of water or electrolyte into the gas space.
Claim 12
Dependent Claim
93 words
A gas diffusion electrode for an electrochemical cell, comprising, an external surface provided with both a catalyst for converting gas to electricity and an electrically conductive material, an internal surface being provided with a hydrophobic material, the hydrophobic material being a cohesive porous plastics layer having pores impermeable to liquid and permeable to gas, a gas space totally sealed about its periphery being defined inside the electrode, said gas diffusion electrode permitting gas to diffuse from and to said sealed gas space and preventing entry of water or electrolyte into the gas space.
Claim 13
Dependent Claim
45 words
A gas diffusion electrode as claimed in claim 10, wherein the peripherally totally sealed gas space is formed as a pocket totally sealed about its periphery, walls of the pocket being sheets of the hydrophobic porous plastics material, the walls being separated by spacer elements.
Claim 14
Dependent Claim
32 words
A gas diffusion electrode as claimed in claim 10, wherein said gas space is defined by a porous body which is coated on an exterior surface with the hydrophobic, porous plastics material.
Claim 15
Dependent Claim
26 words
A gas diffusion electrode as claimed in claim 12, wherein the porous body has greater sized pores than the pores in the exterior porous plastics material.
Claim 16
Dependent Claim
25 words
A gas diffusion electrode as claimed in any one of claims 10-13, wherein the electrode has gradually increasing hydrophobicity from one end to the other.
Claim 17
Dependent Claim
30 words
The electrochemical cell as claimed in claim 6, wherein the portion of the gas diffusion electrode above the electrolyte constitutes at least 5% of the total surface of the electrode.
Claim 18
Dependent Claim
31 words
The electrochemical cell as claimed in claim 6, wherein the portion of the gas diffusion electrode above the electrolyte constitutes at least 10% of the total surface area of the electrode.
Claim 19
Dependent Claim
36 words
The electrochemical cell as claimed in claim 7, wherein the surface of the gas diffusion electrode above the electrolyte level is within the range of 10% to 15% of the total surface area of the electrode.
Claim 20
Dependent Claim
24 words
The electrochemical cell as claimed in claim 1, wherein the electrochemical cell is a metal/oxygen battery, a fuel cell or a metal oxide/hydrogen battery.