Process for adding electrolyte to a fuel cell stack

Patent · Tue Sep 16 04:00:00 EDT 1986

OSTI ID:5353763

Grevstad, P E

This patent describes a process for adding electrolyte to a fuel cell stack such that the stack has a desired operating volume and concentration of electrolyte. The stack consists of elements defining a plurality of fuel cell units disposed one atop the other abutting relationship, the units defining a substantially flat, vertically extending external face. Each unit includes a cell comprising a pair of spaced apart gas porous electrodes with a porous matrix layer sandwiched therebetween for retaining electrolyte during cell operation. Each unit also includes a substantially non-porous separator, the separator being sandwiched between the cells of adjacent units, the steps of: depositing dilute electrolyte of known concentration and from an external source directly onto the external face of the stack while it is in a non-operating mode, the deposited electrolyte being absorbed by capillary action into elements of the stack. The step of depositing continues until all of the electrodes and matrix layers of the stack are fully saturated with the dilute electrolyte at substantially the known concentration; and thereafter, while the stack is in a non-operating mode, evaporating water from the saturated elements under selected conditions of humidity and temperature until a steady state condition is reached. The steady state condition is a condition wherein the stack has the desired electrolyte volume and electrolyte concentration therein.

• Assignee: NOV; EDB-86-165269; NOV-85-025081
• Patent Number(s): US 4612262
• OSTI ID: 5353763
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
300503* -- Fuel Cells-- Materials
Components
& Auxiliaries
ABSORPTION
BATTERY SEPARATORS
CONTROL
DILUTION
DIRECT ENERGY CONVERTERS
ELECTROCHEMICAL CELLS
ELECTRODES
ELECTROLYTES
EVAPORATION
FUEL CELLS
HUMIDITY CONTROL
HYDROGEN COMPOUNDS
MATERIALS
MATRIX MATERIALS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
POROSITY
QUANTITY RATIO
SPACE DEPENDENCE
STEADY-STATE CONDITIONS
TEMPERATURE CONTROL
VOLUME
WATER