Martin Klein

Method for fabricating a battery electrode

This invention is directed to fabrication of electrodes from electrochemically active material prepared by coating non- to low-conductive particles of a metal hydroxide or metal oxide powder with nickel using a electroless nickel coating process. The cell design and electrode formulations provide for individual operation of a vented or low pressure sealed cell and/or for operation of these cells in a stacked array in an outer battery housing.

Electro Energy Bipolar Wafer Cell Battery Technology for PHEV Applications

Electro Energy, Inc. (EEI) has developed a bipolar battery utilizing a patented wafer cell design, applicable to both NiMH and Li-Ion chemistries. This battery is particularly suitable for meeting the high-voltage, high- energy demands of modern and emerging plug-in hybrid vehicles (PHEVs). EEIs battery technology has the potential to provide a rebuttal to the most common argument for not developing and mass-producing PHEVs, which is that presently available battery technologies do not provide sufficient energy density at a low enough cost and in a small enough package to make such vehicles practical. The EEI battery design is such that conventional current tabs, collectors, and inter- cell connections are eliminated, yielding a battery that is smaller and lighter than a comparable non-wafer battery having an equivalent energy density. In addition, the stacked wafer design has lower internal impedance than conventional batteries, allowing for higher discharge rates and less internal heat build-up. The NiMH version of this battery design has already been successfully demonstrated by EEI in the conversion of a Toyota Prius hybrid electric vehicle (HEV) to a PHEV. A next generation PHEV conversion using a Li-Ion wafer cell battery is presently being implemented. This paper will discuss the advantages of the wafer cell design, past experiences and results obtained with the NiMH PHEV conversion, and future expectations for the Li-Ion PHEV conversion.

Bipolar nickel-metal hydride aircraft battery with increased capacity and improved low temperature performance

Electro Energy, Inc. (EEI) has developed a bipolar Ni-MH wafer cell design that has the advantages of reduced weight, with increased capacity, high power and low temperature capabilities over conventional Ni-MH and competing technologies. These advantages make the EEI bipolar Ni-MH the battery of choice to replace the present F16/F18 and other military aircraft batteries. EEls present F-16 battery has 10% reduced weight in the same volume as the existing lead-acid battery, while having 21/2 times the capacity. EEls design of parallel stacks of thin wafer cells results in increased electrode surface area leading to improved high-rate and low temperature capability. The design has shown to be capable of operating at the Air Force minimum temperature requirement of -40°C. This has been achieved by optimizing each of the following variables: 1) metal-hydride alloy; 2) electrode capacity and surface area relationship; and 3) electrolyte composition. Supported by U.S. Air Force Manufacturing Technology Programs, EEI has focused on improving the performance of this battery, while scaling-up the manufacturing processes to meet the demands of the DoD and provide a cost competitive battery.

Pulse Power 350 V Nickel Metal Hydride Battery

Energy storage devices are needed for applications requiring very high power over short periods of time. Such devices have various military (rail guns, electromagnetic launchers, and DEW) and commercial applications, such as hybrid electric vehicles, vehicle starting (SLI), and utility peak shaving. The storage and delivery of high levels of burst power can be achieved with a capacitor, flywheel, or rechargeable battery. In order to reduce the weight and volume of many systems they must contain advanced state-of-the-art electrochemical or electromechanical power sources. There is an opportunity and a need to develop energy storage devices that have improved high power characteristics compared to existing ultra capacitors, flywheels or rechargeable batteries. Electro Energy, Inc. has been engaged in the development of bipolar nickel metal hydride batteries which may fulfill the requirements of some of these applications. This paper describes a module rated at 300 V (255 cells) / 6 Ah. The volume of the module is 23 L and the mass is 56 kg. The module is designed to deliver 50 kW pulses of 10 seconds duration at 50% state of charge. Details of the mechanical design of the module will be presented, along with the results of initial electrical characterization testing. Some discussion of the possibilities for design optimization is also included.