Honda Motor Co., Ltd.

Hiroyuki Ishikawa

Koji Nakazawa

Eiji Haryu

Daisuke Kurashina

Nobuyuki Kawasaki

Yuji Yamakawa

Jun Takeuchi

Hisashi Nagaoka

Masanori Okabe

Hayato Daimon

A differential pressure water electrolysis system includes high pressure water electrolysis cells stacked and fastened in a stacking direction. Each of the high pressure water electrolysis cells includes an electrolyte membrane, an anode feed conductor, a cathode feed conductor, an anode separator, a cathode separator, an elastic member, a hydrogen manifold, a conductive member, a sealing member, a conductive sheet, and an insulation member. The conductive member is disposed between the cathode separator and the electrolyte membrane to provide the hydrogen manifold. The conductive sheet is disposed so as to extend from a first portion between the conductive member and the electrolyte membrane to a second portion between the cathode feed conductor and the elastic member. The insulation member is disposed in a center portion of the cathode feed conductor and between the conductive sheet and the electrolyte membrane.

Differential pressure water electrolysis system

A differential pressure water electrolysis system includes high-pressure water electrolysis cells, first and second end plates, and a high pressure hydrogen manifold. The high pressure hydrogen manifold is provided to distribute hydrogen in a stacking direction. Each of the high-pressure water electrolysis cells includes an electrolyte membrane, an anode current collector, a cathode current collector, an anode separator, a cathode separator, an elastic member, a manifold member, and a cylindrical porous member. The manifold member is disposed between the anode separator and the electrolyte membrane to surround the high pressure hydrogen manifold and includes a seal chamber in which a sealing member is disposed to encircle and seal the high pressure hydrogen manifold. The cylindrical porous member is disposed in the manifold member between the seal chamber and the high pressure hydrogen manifold.

A differential pressure water electrolysis apparatus includes high-pressure water electrolysis cells and a pressing mechanism. The high-pressure water electrolysis cells are stacked in a stacking direction. Each of the high-pressure water electrolysis cells includes an electrolyte membrane, a member, an anode current collector, a cathode current collector, an anode separator, and a cathode separator. The electrolyte membrane has a first side and a second side opposite to the first side in the stacking direction. The member has a surface which has an opening and which is in contact with the electrolyte membrane. The anode current collector is disposed on the first side of the electrolyte membrane. The cathode current collector is disposed on the second side of the electrolyte membrane. The anode separator has an anode chamber in which the anode current collector is accommodated. The pressing mechanism is to press the high-pressure water electrolysis cells in the stacking direction.

Differential pressure water electrolysis apparatus

A water electrolysis system includes a high-pressure hydrogen production unit for electrolyzing water to generate oxygen and high-pressure hydrogen (the pressure of the high-pressure hydrogen being higher than that of the oxygen), and a gas-liquid separation unit for removing water contained in the high-pressure hydrogen. The gas-liquid separation unit is placed on a hydrogen pipe for discharging the high-pressure hydrogen from the high-pressure hydrogen production unit. In addition, the water electrolysis system includes a high-pressure hydrogen supply pipe for transferring dewatered high-pressure hydrogen from the gas-liquid separation unit, a cooling unit, which is placed on the high-pressure hydrogen supply pipe and is capable of variably controlling the temperature of the high-pressure hydrogen to adjust the humidity of the high-pressure hydrogen, and a control unit.

Method for operating the water electrolysis system

In a method of stopping an operation of a water electrolysis system, an on-off valve disposed in a pressure release line communicating with a cathode side of an electrolytic membrane is opened while an electrolytic current is applied between power feeders to electrolyze water for generating oxygen on an anode side of the electrolytic membrane and high pressure hydrogen having a higher pressure than a pressure of the oxygen on the cathode side. A value of the electrolytic current is reduced in a predetermined cycle or continuously. One of a specific resistance and conductivity of water to be supplied to the high pressure hydrogen producing apparatus is detected. The value of the electrolytic current is increased if the specific resistance is equal to or lower than a first predetermined value, or if the conductivity is equal to or higher than a second predetermined value.

Water electrolysis system and method of stopping operation of water electrolysis system

Water electrolysis system and method for operating the same

A high-pressure hydrogen producing apparatus includes a cell device and a piston member. The piston member is to apply a pressing force to the cell device from an end of the piston member in a stacking direction in which unit cells are stacked. The piston member is provided with a first hydrogen passage, at least one second hydrogen passage, and a hydrogen lead-out passage. The first hydrogen passage and the second hydrogen passage are spaced at substantially equal angular intervals on a virtual circle centered on a center of an end face of the piston member.

High-pressure hydrogen producing apparatus

A hydrogen electrolysis apparatus includes a stack of unit cells each having a membrane electrode assembly sandwiched between an anode separator and a cathode separator. The anode separator has a first flow field which is supplied with water, and the cathode separator has a second flow field which produces high-pressure hydrogen through an electrolysis of the water. The cathode separator also has a first seal groove defined therein which extends around the second flow field and a first seal member inserted in the first seal groove. The first seal groove and the second flow field are held in fluid communication with each other through passageways. The passageways keep the first seal groove and the second flow field in direct fluid communication with each other in bypassing relation to the boundary between the cathode separator and a solid polymer electrolyte membrane.

Growing community of inventors

Wako, Japan

Hiroyuki Ishikawa