Use of Aqueous Double Layer Ultracapacitor using Hybrid CDI-ED Technology for the use in Hybrid Battery Systems

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1 Use of Aqueous Double Layer Ultracapacitor using Hybrid CDI-ED Technology for the use in Hybrid Battery Systems Overview By Robert Atlas, Aqua EWP,LLC. September 2007 Aqua EWP. has for the last 10 years using a version of the Ultra capacitor (patents pending) in the form of Capacitive Deionization used in water purification. In this application the charge required to purify is proportional to the amount of mass deposited on the surface of the electrodes (reference The charge is not recovered. Aqua EWP has made 1000 s of cells for water purification for use all over the world. Most, if not all battery technology today uses metal based electrodes and organic electrolytes that are hazardous to the environment, have long charge times and are expensive. Most chargeable batteries are Nickel metal Hydride or Lithium ion and must use organic composition for the electrolyte. Water to these technologies degrades the electrodes. Characteristically the present technology has long charge and discharge times. Based on the intellectual property associated with the EWP (Electronic Water Purifier) an ultra capacitor (patent pending) has been developed that is fairly inexpensive compared to current technology available. The electrodes are made of activated carbon and carbon nanotubes in a housing with an integral polymeric coating. The electrolyte is a water soluble organic with an extraordinary common mineral that is non hazardous to the environment. The method of construction has very little free electrolyte. The bulk of the electrolyte is between the electrode layers. The product, for now is called EWP brand Power Cell. The experimental data shows that the Power Cell has twice the power when measured as watts of power delivered per minute of load, than any rechargeable battery technology on the market today. The cost of the Power Cell today, is 1/10 th that of other battery recharge technologies. Depending on the discharge and recharge load, the Power Cell can charge and discharge as much power at close to 100% efficiency (power in to charge vs. power out to discharge). It appears that this technology could be well suited to any rechargeable battery that has a generator (fired by gas, propane, hydrogen etc..) hybrid recharger. Applicable markets could be HEV (hybrid electric vehicles), regenerative braking systems, lift applications, telecommunications, military (HEV or weapons systems), marine (recreational or large vessels), oil and gas drilling, industrial, utility and UPS backup power supplies, to name a few.

2 Technical Discussion The ultra capacitor (Ultra Cap) is starting to challenge traditional rechargeable batters such as lithium based or Nickel based chemistries. Many of the tier 1 automotive companies are now experimenting with Ultra Caps for the recovery of kinetic energy from braking The Ultra Cap has come a long way from its original invention in 1745, but is limited by its fast charge and discharge characteristic. It is a poor battery because present Ultra Caps can t hold charge very long so their discharge times are short (30 seconds) compared to recharge times (1 to 2 minutes). The Ultra Caps made by others, while claimed to be environmentally safe, but still uses hazardous electrolyte salts and fluids. A 2,500 farad capacitor is considered an Ultra Cap. Aqua EWP has made Ultra Caps no smaller than 2,500 farads and as large as 65,000 farads in a water purification configuration. We should probably call our capacitors Mega Caps, except that this technology doesn t have the fast discharge characteristic. While many manufacturers are further out on the experimental edge of capacitors such as Lithium Gel based capacitors, there appear to be three major players, Mawell, Ness and Panasonic. Lithium Ion batteries deliver more energy faster and for longer periods of time than Ultra caps, but only half the delivery rate of the Power Cell. While the Lithium Ion battery discharges for 3 hours, they take 3 hours to recharge. The Power Cell discharges for two minutes (depending on discharge load) and recharges in one minute. Because the cost is so much less, a duplex system can be designed charging one bank of Power Cells while the other bank is being discharged under load. The Lithium Ion batteries have explosion probability, environmental disposal hazards, short life and high expense. The Power Cell can discharge fast (or slow) so it can deliver power fast for peak demand, such as a vehicle accelerating or delivering power to a backup system prior to the time delay of a generator reaching its peak average power delivery rating. In order to minimize weight, the device \must deliver 5 wh/kg (watt hours per kilogram).. have a power density of 600 w/kg..have a useful life of 100,000 cycles.and be 90% efficient (power compared to power out) 1. The Power Cell meets these requirements delivering 2,600 w/kg per minute of use, life of 1,000,000 cycles and is 98% efficient. The power density is 10 times that of Lithium Ion batteries. Nickel Cadmium (NiCad) batteries are capable of supplying high power applications, but are far more expensive that other rechargeable batteries and have short life cycle. Our estimate of available power, based on experimental data is that 75% of the power in the power cell can be converted to useful work between the range of 2.5 VDC to 1.5 VDC at a regulated voltage of 2.0 VDC. There is quite a bit of optimization that can improve the useful power based on chemistry of the electrolyte, electrolyte fluid, concentration and electrode chemistry. It is highly probable that the stated performance can easily double with some laboratory development work.

3 Comparison of Key Metrics (data from various sources on the web) Useful volts Voltage energy power recharge discharge Cost of cell of cell weight density time Time wh/kg w/kg hrs hrs $/wh Ultracapacitors* , min 0.5 min Li ion gel* $ 800 Li Co hr 3 hr $ 2, /hr Power Cell min 2 min $ /hr NiCad hr 3 hr $ /hr Ni MH hr 3 hr $ 250 Zn air Lead Acid hr $ 150 * Too new still in development The Power Cell Power Cell Based on the intellectual property associated with the EWP (Electronic Water Purifier) an ultra capacitor (patent pending) has been developed that is fairly inexpensive compared to current technology available. The electrodes are made of activated carbon with an integral polymeric coating. The electrolyte is a water soluble organic with an extraordinary common mineral that is non hazardous to the environment. The method of construction has very little free electrolyte. The bulk of the electrolyte is between the electrode layers. The same operating principles of the Electronic Water Purifier apply the same as the double layer aqueous ultra capacitor except there is not flow.

4 Quick Charge Battery or Hydrogen Generation for Fuel Cells based on water (patent pending) 100 fold improvement: 10X better than Lithium based technologies at 1/10 th cost Step 1 - Water Chemistry There is no comparable technology on the market today and is marketed under the EWP brand name by Aqua EWP. A dissolved mineral in an electrolyte solution (water based). The dissolved mineral will be removed and the mass transferred to the electrode.

5 Step 2 (charging cycle) or Generate Hydrogen 2 CC/gram carbon Electrodes used are made from activated carbon. When these electrodes are layered using a DC power supply, the individual electrodes are charged with different polarities. The dissolved mineral in the electrolyte have polarity charges are attracted to the opposite polarity of the electrode, thus removing the dissolved minerals from the electrolyte. These dissolved minerals are absorbed electrochemically on the electrode surface creating the charge due to mass deposition. When sufficient dissolved minerals are transferred onto the electrodes, the charge increases Step 3 Regeneration (discharge Cell i.e. conversion to useful work) The minerals are released from the surface of the electrode simultaneously as discharge occurs and re-dissolves back into the electrolyte solution. This charge is then converted to useful work such as driving a DC motor.

6 An Ultra Cap typically discharges and charges rapidly, lending the technology to have duplex battery banks, where one is charging while the other is discharging. The individual cells, inside the battery bank can be hooked up in series, where each cell can operate a 2 VDC nominally. The charge (or amps) is proportional to the amount of mass transferred between the electrolyte and the electrodes. The mechanism of mass transfer is diffusion. Some of the characteristics Charges in 1 minute and discharges over 2 minutes (depending on load). For simplicity half the time the voltage is over 2 VDC and the other half of the time the voltage is between 1 VDC and 2 VDC. The Power Cell has a discharge characteristic that can give all it s power in a matter of seconds, or have a controlled discharge over a couple of minutes, with a 1 minute charge time. The individual cells can be connected in series inside the battery to make a power cell that has for 40 amps and 12 VDC. The size would be 4 square x 6 long. Total weight is estimated at 2.5 kg (including electrolyte, holder and terminals) without the voltage control electronics. The power cell will need a buck-boost circuit designed to average 12 VDC because the Power Cell s range will be 9 to 15 VDC above 2 VDC the buck circuitry is needed and from 1.5 VDC to 2 VDC the boost circuitry is needed. Recharge can be done at either constant voltage or current using standard power supplies using a generator. Recharging rated for 1,000,000 cycles. Actual life is not known. Electrolyte is non hazardous with a freezing point of >50 deg C and a boiling point greater than 80 deg C. Technology Development Program A cell has been made and tested, although not optimally designed has the following characteristics 8 VDC for 2 minutes 8 Amps 2.5 Volts max 2 Volts useful Useful load 25 grams-carbon 150 g total weight $28 Cost 1,250 farads The electrolyte solution is water soluble (but not water) and the salt is a very common mineral. Neither of these materials is hazardous if exposed to, short term or long term. The freezing point is -50 deg C and the boiling point is 80 deg C.

7 Short term-next 3 months 1. The cell is undergoing design changes of electrolyte solution, so that we can obtain an amperage of 10 to 15 amps at an average of 2 vdc per individual cell. 2. A cell that is quadruple in size would yield could drive a 2 VDC load of 32 amps for two minutes. When 6 cells are configured in series into one battery holder the power cell would generate 12 VDC power at 32 amps. For now, this is the size we are developing. 3. The packaging is to be designed on how to configure 6 individual cells, connected in series for the Power Cell. 4. The Power Cell will undergo cycle testing under load using a 12 VDC motor at 12 amps. A recharging system, instrumentation, controls and data acquisition will also be designed. 5. (12)-500 watt Power Cells will be manufactured (Aqua EWP has the required inventory, manufacturing process and know-how) and installed on a Golf Cart. 6. Redesign web site to include the Power Cell and link up key words to the search engines Golf Cart Prototype Design using Aqueous Ultracapacitor Charging System A prototype golf cart is being built based on this technology. Design Ezgo golf cart 6 to 8 Power Cells rated at 36 VDC and 40 amps. Recharged done by 1500 W generator using AC/DC power supplies controlled by a PLC. Estimated weight of Golf Cart o Golf Cart 600 lbs o Charging System 150 lbs. (70 lbs is the generator) o Total 750 lbs Estimated mileage 150 mpg Completion date 2008

8 Electric Golf Cart Specifications Motor: 36V, 1 kw Size: 2360 x 1180 x 1700mm Weight (excluding batteries): 254kgs Seat capacity: 2 persons Maximum speed: 15 to 22kph Maximum loading: 362kgs Minimum turning diameter: 570cm Maximum gradient: 30 Bibliography 1. Organic Electrolytic Ultra capacitors on Aluminum/Carbon Electrode Technology, Maxwell Laboratories 2. Ultracapacitors Challenge the Battery, John M. Miller, WorldandI.com,