Laptop computer with fuel cell

One of several recently presented prototypes of a notebook personal computer powered by a micro-DMFC is shown in Fig. 4.14. A replaceable methanol cartridge is placed behind the computer, and the 280-cm DMFC is placed under the laptop keyboard. The fuel cell produces 14 W at 12 V, and if the methanol volume is 30 cm (judged from photo), then the storage capacity is 142 Wh. This would allow the computer to be operated for 14 h at an average consumption of 10 W. Many computer manufacturers, notably in Japan, have recently demonstrated similar DMFC notebook prototypes, including some with a more elegantly integrated methanol container than the one on the early model shown in Fig. 4.14. 

Researchers at Lehigh University are developing a methanol reforming silicon reactor with a palladium membrane for a hydrogen purification system built using semiconductor fabrication techniques. The device is designed to produce hydrogen for fuel cells for portable electronic devices, such as laptop computers and cell phones. 

Power requirements of portable hydrogen equipment such as cameras, mobile phones or laptop computers currently covered by batteries, typically of lithium ion type, could with a small fuel cell and some 10-20 g of directly or indirectly stored hydrogen prolong operational time by a factor of 5-10. A discussion of such options using direct methanol fuel cells is made in section 4.6. 

Consuming patterns have over recent years seen a dramatic increase in the use of portable equipment for entertainment and work (such as music and video players, laptop computers and mobile phones with multi-functionality). This has increased the demand for batteries, but at the same time found limitations of the battery technology that seem difficult to avoid even with increasing conversion efficiencies. Fuel cells with small-scale stores are an obvious solution to these problems, because the technical performance is already far beyond that of batteries (e.g., operating a state-of-the-art laptop computer for a few days rather than a few hours). The difference between these otherwise similar technologies is the external storage of chemicals for a fuel cell versus the internal storage in batteries. 

Figure 4.14. Laptop computer powered by a direct methanol fuel cell. The methanol cartridge is at the back. (From Y. Kubo, NEC Corp., (2004). Micro fuel cells for portable electronics. In Proc. 15 World Hydrogen Energy Conf., Yokohama. OlPL-22, Hydrogen Energy Soc. Japan. Used with permission.)...

Recently we have developed spray-pulsed reactors equipped with alumi-monolith (alumite) catalyst plates for the efficient supply of hydrogen, using organic hydrides, to the micro-fuel cells of portable electrical appliances such as mobile phones, laptop computers and nurse robots, as shown in Fig. 

Figure 6.12 Developmental miniature methanol fuel cells for electronic applications (a) Toshiba, for digital audio players and wireless headsets for mobile phones (b) NEC, for mobile phones (c) Hitachi, for personal digital assistants (d) Motorola, with methanol capsules, for mobile phones (e) Casio, for laptop computers.

In Korea, Samsung Advanced Institute of Technology is developing butane-powered fuel cells to act as power supplies for small electronics. As of 2006, the fuel cell produces a maximum of 100 watts (W) of electricity. The 220-gram (g) liquefied butane cartridge can power a laptop for more than 20 h. Samsung plans to commercialize the butane fuel cell in 2007 and increase the maximum power output to 300 W. In a partnership with IBM, Sanyo produced a DMFC for an IBM ThinkPad laptop computer. The protot)q)e, introduced in April 2005, provides up to 8 h of power and works with a battery in a hybrid system. 

Fuel cells can compete with batteries and generators for portable use, from a few kilowatts to power an emergency home generator down to a few watts to power a laptop computer." NEC Corporation and Toshiba have publicly demonstrated protot pes of this sort, and the first few products should enter... 

Nevertheless, portable fuel cells are in their infancy. Investment costs to generate 1 kilowatt are stiU very high, around 10,000 to 100,000 per produced kilowatt. However, portable fuel cells should become cost competitive ( 5,000/kW) with lithium-ion batteries, commonly used in laptop computers,... 

Wee JH (2007) A feasibility study on direct methanol fuel cells for laptop computers based on a cost comparison with lithium-ion batteries. J Power Sources 173 424-436... 

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