Abstract: A rechargeable battery, module or a pack, having different levels of internal resistance that operate at different temperatures are disclosed. In a subfreezing environment, the battery can exhibit high resistance which once operated or activated, generates heat internally to warm up the battery quickly. Once the batter reaches normal operating temperatures, the battery can switch to a low resistance operating mode, thereby delivering superior power and energy despite operating in a very low ambient temperature.

Abstract: A rechargeable battery whose ohmic resistance is modulated according to temperature is disclosed.

Abstract: A rechargeable battery that features two or more levels of internal resistance according to various temperature ranges is disclosed.

Abstract: A battery with three types of terminals is disclosed. The terminals include at least one negative terminal, at least one positive terminal, and at least one sensor terminal. The negative and positive terminals carry current during battery operation, while the sensor terminal is used to sense, communicate and/or control certain aspects of the battery. The sensor terminal can also be connected to external electronic units for sensing, communication and control of the battery usage.

Abstract: A battery system is disclosed that can internally heat a battery by consuming minimal battery energy and with short heating times.

Abstract: A cathode for use in a direct oxidation fuel cell (DOFC) comprises a gas diffusion medium (GDM) including a backing layer and a microporous layer comprising a fluoropolymer and an electrically conductive material, wherein loading of the fluoropolymer in the microporous layer is in the range from about 10 to about 60 wt. %. In use, a concentrated solution of a liquid fuel is supplied to an anode and an oxidant to the cathode of the fuel cell, and the fuel cell may be operated at a low oxidant stoichiometry ?c not greater than about 2.5.

Abstract: A controller in a charging control system controls a charger to heat a battery at a low temperature by pulse charging and discharging up to a desired temperature and then moves to a normal charging mode. The controller calculates an ion concentration of an active material at electrode portions of the battery on the basis of the temperature data and the electric current data obtained, switch the pulse charging and discharging between a charging mode and a discharging mode on the basis of a pulse width when the ion concentration reaches a threshold.

Abstract: A direct oxidation fuel cell (DOFC) having a liquid fuel and an anode electrode configured to generate power. The anode electrode includes a gas diffusion layer (GDL) and a microporous layer, such that a decrease in the porosity of the GDL achieves an increase in the power density of the DOFC.

Abstract: A cathode for use in a direct oxidation fuel cell (DOFC) comprises a gas diffusion medium (GDM) including a backing layer and a microporous layer comprising a fluoropolymer and an electrically conductive material, wherein loading of the fluoropolymer in the microporous layer is in the range from about 10 to about 60 wt. %. In use, a concentrated solution of a liquid fuel is supplied to an anode and an oxidant to the cathode of the fuel cell, and the fuel cell may be operated at a low oxidant stoichiometry ?c not greater than about 2.5.

Abstract: A proton (H+)-conducting hydrocarbon (HC)-based polymer electrolyte membrane (PEM) having first and second oppositely facing surfaces comprises a HC-based membrane with at least one perfluoropolymer incorporated on or within at least the first and second surfaces. A method for fabricating the PEM comprises surface treating a HC-based polymeric membrane sheet via immersion in an aqueous solution or dispersion of said at least one perfluoropolymer, followed by drying of the surface treated polymeric membrane sheet.

Abstract: A direct oxidation fuel cell (DOFC) and a method of fabricating the DOFC such that the DOFC reduces overpotential. The DOFC includes a cathode electrode; an anode electrode; and a polymer electrolyte membrane (PEM) sandwiched between the cathode and the anode. Each of the cathode electrode and anode electrode include a catalyst layer and a gas diffusion layer (GDL) and the anode electrode catalyst layer includes platinum (Pt), ruthenium (Ru) and a small amount of SnO2 supported on carbon powder.

Abstract: A direct oxidation fuel cell (DOFC) having a liquid fuel and an anode electrode configured to generate power. The anode electrode includes a phase separation layer (PSL) positioned between a fuel channel plate and a GDL. The PSL can include at least one porous layer to improve fuel distribution and increase fuel cell performance.

Abstract: A controller in a charging control system controls a charger to heat a battery at a low temperature by pulse charging and discharging up to a desired temperature and then moves to a normal charging mode. The controller calculates an ion concentration of an active material at electrode portions of the battery on the basis of the temperature data and the electric current data obtained, switch the pulse charging and discharging between a charging mode and a discharging mode on the basis of a pulse width when the ion concentration reaches a threshold.

Abstract: A direct oxidation fuel cell (DOFC) system comprises at least one fuel cell assembly including a cathode and an anode with an electrolyte positioned therebetween; a source of liquid fuel in fluid communication with an anode inlet; an oxidant supply in fluid communication with a cathode inlet; a liquid/gas (L/G) separator in fluid communication with anode and cathode outlets for: (1) receiving unreacted fuel and liquid and gaseous products of electrochemical reactions at the cathode and anode, and (2) supplying the unreacted fuel and liquid product to the inlet of said anode; and a control and/or regulation system for determining a fuel efficiency value of the DOFC system during operation and determining and regulating and/or controlling oxidant stoichiometry of the DOFC system at an appropriate value in response to the determined fuel efficiency value.

Abstract: A proton (H+)-conducting hydrocarbon (HC)-based polymer electrolyte membrane (PEM) having first and second oppositely facing surfaces comprises a HC-based membrane with at least one perfluoropolymer incorporated on or within at least the first and second surfaces. A method for fabricating the PEM comprises surface treating a HC-based polymeric membrane sheet via immersion in an aqueous solution or dispersion of said at least one perfluoropolymer, followed by drying of the surface treated polymeric membrane sheet.

Abstract: A high power density direct oxidation fuel cell (DOFC) with comprising an anode electrode with a microporous layer (MPL) configured to alleviate cathode dryout and thus reduce electrode resistance in the cathode that interfaces with a hydrocarbon membrane. The MPL is configured to alleviate cathode dryout by comprising a fluoropolymer and an electrically conductive material, wherein the MPL is loaded with fluoropolymer in the range from about 10 to about 25 wt. %.

Abstract: A direct oxidation fuel cell (DOFC) system, comprises at least one fuel cell assembly including a cathode and an anode with an electrolyte positioned therebetween; a source of liquid fuel in fluid communication with an inlet of the anode; an oxidant supply in fluid communication with an inlet of the cathode; a liquid/gas (L/G) separator in fluid communication with outlets of the anode and cathode for: (1) receiving unreacted fuel and liquid and gaseous products, and (2) supplying a solution of fuel and liquid product to the anode inlet; and a control system for measuring the amount of liquid product and controlling oxidant stoichiometry of the system operation in response to the measured amount of liquid product. Alternatively, the control system controls the concentration of the liquid fuel in the solution supplied to the anode inlet, based upon the system operating temperature or output power.

Abstract: A direct methanol fuel cell unit is provided with a fuel cell including an anode, a cathode with a hydrophobic microporous layer, an electrolyte membrane put in-between, and a fuel supply path supplying fuel to the anode. The fuel supply path is provided with an upwind water barrier preventing back-diffusion of water and a gas flow path channeling gas generated at the anode and disposed between the barrier and the anode. A water-rich zone is formed between the water barrier and the cathode microporous layer. Water loss from either side of this zone is eliminated or minimized, thereby permitting direct use of highly concentrated methanol in the fuel flow path with good fuel efficiency and power performance. The cell unit can be applied equally well to both an active circulating air cathode and an air-breathing cathode.

Abstract: A direct oxidation fuel cell (DOFC) system comprises at least one fuel cell assembly including a cathode and an anode with an electrolyte positioned therebetween; a source of liquid fuel in fluid communication with an anode inlet; an oxidant supply in fluid communication with a cathode inlet; a liquid/gas (L/G) separator in fluid communication with anode and cathode outlets for: (1) receiving unreacted fuel and liquid and gaseous products of electrochemical reactions at the cathode and anode, and (2) supplying the unreacted fuel and liquid product to the inlet of said anode; and a control and/or regulation system for determining a fuel efficiency value of the DOFC system during operation and determining and regulating and/or controlling oxidant stoichiometry of the DOFC system at an appropriate value in response to the determined fuel efficiency value.

Abstract: An anode electrode for use in a fuel cell comprises a stacked structure including, in sequence: a catalyst layer, a hydrophobic, microporous layer (“MPL”), a porous gas diffusion layer (“GDL”), and an anode plate with at least one recessed fuel supply-fuel/gas exhaust channel formed in a surface thereof facing the GDL, wherein the stacked structure further comprises at least one hydrophobic region aligned with the at least one recessed channel. The electrode is useful in direct oxidation fuel cells and systems, such as direct methanol fuel cells operating with highly concentrated liquid fuel.