Millennium cell

Millennium Cell has reported that their NaBH4-based hydrogen on demand system possesses a system gravimetric capacity of about 4wt%. Similarly to other material approaches, issues include system volume, weight and complexity and water availability. 

Figure 5.5 Operating scheme of a commercial NaBH4-PEMFC system (With permission from Millennium Cell.)...

The product of the decomposition is, like in the Millennium Cell system, sodium metaborate. The system shows the same problems for the regeneration of NaBH4 from an aqueous solution of metaborate as described below. One advantage of the direct borohydride fuel cell systems is that platinum as catalyst is not needed. Unfortunately, depending on the temperature of the solution, some hydrogen gas is produced in a side reaction. However, this hydrogen can be piped out or can be used as additional fuel in a subsequent PEM fuel cell. 

The US company Millennium Cell has developed a prototype fuel cell used to power an IBM ThinkPad. Currently, the prototype runs for only 3 h, but Millennium aims to increase the running time to 8 h. The company expects the fuel cell to cost approximately 150, about the same price as a standard laptop battery. NEC, a Japanese company, has multiple versions of its DMFC laptop prototype. The most current model, released in October 2005, is 20% smaller than the 2004 model and has a power output density of 70 milliwatts (mW) per square centimeter, a 40% improvement on the previous model. One 250 Cm methanol cartridge can power the laptop for 10 h. The company plans to commercialize the laptop in 2007. 

Millennium Cell [36.3] has patented boron-based batteries. The anode reaction is... 

Another method that is used is that of the Hydrogen on Demand system promoted by Millennium Cell, and promoted at their website. This uses a single-pass catalyst, rather than the recirculation system of Figure 8.25. A major advantage of this is that the tank of fresh solution can be topped up at any time. A disadvantage is that two tanks are needed - the second one for the spent solution that has passed over the catalyst. 

The companies, such as Millennium Cell Inc., who are hoping to commercialise this process are working hard on this problem of production cost - finance and energy. If they succeed, there will be a useful hydrogen carrier, but until the costs come down by a factor of at least 10 this method is only suitable for special niche applications. 

FIGURE 16.2 Schematic of HYDRCXIEN-ON-DEMAND system, based on diagrams published by the former company Millennium Cell Inc. 

Millennium Cell and Horizon poised to unveil HydroPak. Fuel Cell Today. Available at ht //www.fuelcelltoday.com/online/news/articles/2008-01/Millennium-Cell-and-Horizon-pois. Accessed 17 Mar 2009... 

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