|
|
Baby Steps to our FutureMicro Fuel Cells for Mobile Devices Envision a cold winter morning with gusty sleet filled wind. You're running behind schedule as you jump into the car headed to work to meet with the boss about your promotion and when you turn the key all you hear is click, click, click. Words can not describe the range or intensity of emotions that shoot through one's mind when the battery is dead. The same could almost be said if one is under a great deal of pressure to complete field measurements and your laptop battery dies. Or if you are on a business trip and you need to check an address or phone number and your PDA battery goes dead. And almost everyone has experienced a dead cell phone battery. Finally, what about those digital cameras with the LCD displays? These devices seem to have the shortest battery life of all devices and when they are dead they tend to conjure up the same emotions as when one hears click, click, click. Even as battery technology has evolved from the non rechargeable alkaline battery to the rechargeable nickel cadmium (NiCad) and nickel metal hydride batteries (NiMH) and later the Lithium Ion battery (Li ion), we continue to see improved performance in charge density, recharge time, recharge cycle life, size and weight. The latest advancement in storage batteries are the Lithium Polymer (Li Polymer) and Lithium Ion Polymer (Li Ion Polymer) both of which promise even greater performance. But what if you didn't have to mess with toting around an extra bulky battery or having to wait for the long delay in recharging. What if you could just pop in a small cartridge the size of a Bic lighter or ink jet cartridge and be good to go for another 40 hours. [1] This is the potential that fuel cells offer with continued research and development. Good stuff? You bet! So what is a fuel cell and how does it work? Background The fuel cell was first described in 1839 by Sir William Grove and later advanced and popularized by the NASA space flights. Currently, fuel cells have certainly gained the attention of the battery industry. A lot of research has gone into fuel cell technology and table 1 list the various types of fuel cells that have been developed to date.
How They Work A fuel cell converts chemical energy directly into electrical energy. Most, but not all, fuel cells generate electricity by the combining hydrogen and oxygen. One pumps hydrogen in one side and oxygen in the other and you get electricity. The only by-products are carbon dioxide, water and heat from the reaction. All fuel cells are geometrically differently but since the mobile device industry is primarily interested in the Direct Methanol Fuel Cell (DMFC) we will focus our attention on that type of device. [2] Direct Methanol The DMFC uses a dilute mixture of methanol with water as a fuel source. As the mixture is pumped into one side of the cell the anode catalyst strips the Hydrogen atom from the mixture. As the atom approaches the electrolyte only the hydrogen ion (or proton) is allowed to pass into the electrolyte medium. The electron is stripped away from the atom and is conducted through the anode to the electrical load and then returned via the cathode. As the hydrogen ion progresses through the electrolyte it reaches the cathode where it recombines with the returning electron. Then as the hydrogen atom progresses through the cathode it reaches the air delivery channel where the hydrogen combines with the oxygen in the air to form water. The figure below illustrates this process.
Prototypes There have been a number of fuel cell announcements in the last year or so and the following just list a few to give you an indication as how quickly this technology will make it to the market place. The March 2003 announcements were made at the CeBit conference in Hamburg , Germany . Feb. 2002, Toshiba unveiled a fuel cell prototype that powered a GENIEe PDA for 2 hours. The PDA cradle type unit has two tanks, one for methanol and the other for water. Reportedly, the production model is expected to run 3-5 hours with a maximum output of 8 watts. Toshiba hopes to complete development of this product and have a production unit by 2005. Mar. 2003 Toshiba announced the world's first DMFC prototype for PC with an average 12 watts output and maximum output of 20 watts and could achieve 5 hours operation with a single 50cc fuel cartridge. Toshiba also indicated the device was capable of powering PDAs, cell phones and other portable devices. Toshiba hopes to have the model in production by 2004. Mar. 2003 CONSEL Case Solutions in conjunction with SFC Smart Fuel Cell AG has developed a case with an integrated fuel cell capable of running a laptop for 7 hours on one 125ml methanol cartridge. The case can accommodate 7 cartridges that can be hot swapped for a total of 50 hours. They plan to introduce the 'Marathon Case' to the market in 2004. Mar. 2003 Medion and SFC Smart Fuel Cell AG jointly developed an auxiliary power supply for laptops, which runs 3 times longer than conventional batteries. Once the cartridge is empty it can be hot swapped without operational interruption. Medion plans to market the product as 'Energy Docking Station' in 2004. Jun. 2003, NEC revealed their prototype laptop that runs on a micro fuel cells instead of batteries. They indicated this system will initially run 5 hours on a single 300cc methanol cartridge that can be hot swapped. NEC hopes to introduce a PC in 2 years that will operate for 40 hours. Commercialization of their prototype is expected in 2004. Aug. 2003 MTI unveiled a fuel cell prototype the size of a deck of cards that would recharge laptops, PDAs, cell phones, digital camera and other similar devices. The devices would provide electricity and would require a companion battery in the mobile device. The electricity supplied from the fuel cell may allow laptops users to work away from an electrical outlet for about 10 times longer than they can currently. This unit is expected to be in production by 2004 and marketed as a 'Portable Power Supply'. Sep. 2003, NEC announced a 20% reduction of their portable fuel cells for notebooks. The new fuel cell can average 14 watts with a maximum of 24 watts delivered at 12 volts output. The latest device only weighs 900 grams of which 300 grams are fuel. The company indicated they still intend to make this product available in 2004. The company also reiterated their goal of delivering a 40 hour fuel cell for laptops before the end of 2005. Oct. 2003, Toshiba announced their latest fuel cell development was capable of 1 watt per hour for 20 hours of operation using a hot swappable 25cc fuel cartridge containing a high concentration of methanol. The new technology has caused some manufacturing delays and the product will not be available until 2005. Micro fuel cells are a hot item and several other companies have research and development programs underway. Here are some of the other companies that have been mentioned in the references, Hitachi , Casio computers, Motorola, Sony and Samsung all of which have their own products in development. Regulatory Besides technical hurdles there are a couple of regulatory hurdles that need to be addressed before DMFC fuel cells will fly with passengers. Methanol is a flammable liquid and is therefore a controlled substance in the eyes of the Department of Transportation (DOT). However, in 10/4/2002 the DOT ruled methanol fuel cells would be permitted for air transport. This is the first step; however, the FAA has yet to rule on the safety of methanol in the cabin area of the aircraft. Furthermore, airlines have yet to determine if they will permit the substance on their aircraft indicating they would not permit the device if it could interfere with the aircraft handling. [3] Pricing The cost of methanol should not be an issue. Market data for 2002 indicated that methanol production stood at 33.7 million tons/year and wholesale spot market price at 33 cents/gallon. The cost of a re-fill cartridge won't be driven by the cost of methanol but instead by the cost of package and handling and even perhaps the novelty of it. Projections indicate a refill cartridge could cost around $3-5. Reportedly, the initial cost of a fuel cell replacement power supply could run $200 as compared to $120-$180 for a traditional battery. [4] Future From historical data Radio, TV and PCs were adopted at 4% per year linearly up to 80% of market saturation. Li Ion batteries were adopted at a much faster rate; 1.5% in 1994 and 72.1% in 1997 or 23.5% over a 3 year period Allied Business Intelligence (ABI) made the following predictions about micro fuel cells. In 2004 there will be 2000 fuel cell laptops. In 2008 that number is expected to jump to 1 million laptops and $150 million in revenue. In 2011 that number is expect to be at 120 million and $1.2 billion in sales. Several months after making their first projection ABI revised their projections to 5000 units in 2004/2005 and 200 million by 2011. From these projections and company marketing information we can expect to see the fuel cell establish a foothold in 2004/2005. This is not too early because each generation of mobile device is requiring a higher demand for power. Faster CPUs are driving this need along with higher resolution displays, wireless networks and other features the manufactures would like to add to existing equipment. In Closing In the near future we will see cell phones with fuel cell power supplies that will delivery 20 hours of talk time. Teenagers may very well be the first group to adopt this technology. Where else can they find a cell phone power supply that matches their talk time minutes. References
All 'Baby Steps to our Future' articles are archived at www.hal-pc.org/~seeker/future . |
2004 Ron Fenley worked as an engineer/analyst and retired in 1999. Ron moved to the country and now pursues his interest in computers, basic science and technology. Ron has been a computer enthusiast for 20 years and has been a HAL-PC member for about half that time. Ron can be reached at future@hal-pc.org
|
