Abstract: Improved fuel cell systems comprise a fuel delivery system having a fluidization apparatus and a fluidization pump for creating an electrolyte flow suitable for fluidizing at least a portion of the fuel particles located within the fluidization apparatus. Due to the presence of the fluidization pump and the fuel delivery pump, the degree of fluidization of the fuel particles can be controlled independently of the overall electrolyte flow rate provided to the cell stacks. In other words, the mass flow rate of fuel particles through the fuel cell can be varied independently from the total flow rate through the fuel cell system. The fluidization of fuel particles can facilitate suitable mixing of fuel particles and electrolyte and can prevent fuel particle agglomeration, which can clog the fuel cell piping system.

Abstract: A method of and system for flushing one or more cells or components thereof in a particle-based electrochemical power source is provided. Reaction solution is delivered to and withdrawn from the one or more cells when the electrochemical power source is in a standby mode of operation.

Abstract: Improved fuel cell systems comprise a fuel delivery system having a fluidization apparatus and a fluidization pump for creating an electrolyte flow suitable for fluidizing at least a portion of the fuel particles located within the fluidization apparatus. Due to the presence of the fluidization pump and the fuel delivery pump, the degree of fluidization of the fuel particles can be controlled independently of the overall electrolyte flow rate provided to the cell stacks. In other words, the mass flow rate of fuel particles through the fuel cell can be varied independently from the total flow rate through the fuel cell system. The fluidization of fuel particles can facilitate suitable mixing of fuel particles and electrolyte and can prevent fuel particle agglomeration, which can clog the fuel cell piping system.

Abstract: A method of and system for flushing one or more cells or components thereof in a particle-based electrochemical power source is provided. Reaction solution is delivered to and withdrawn from the one or more cells when the electrochemical power source is in a standby mode of operation.

Abstract: A novel fuel particle feeding mechanism that significantly improves operation of a refuelable electrochemical power source is provided. One embodiment of the mechanism provides an input of electrolyte and electrochemically active particles into one or more electrochemical cells through a feed tube. The feed tube has several embodiments that improve the flow of electrolyte and particles, and the even and complete settling of particles into individual cell cavities. Each cell cavity is completely filled, evenly and without clogging when open, and fluid communication between cell cavities is completely cut off when closed, to prevent short-circuiting of the power source during discharge or standby. Means are provided to prevent clogging of the feed tube with fuel particles, to promote complete filling of the cell cavities with fuel, and to prevent fuel particles from prematurely flowing out of the cell cavities. A method of operation is also described.