Micro Fuel Cells vs Rechargeable Batteries

Digital devices are growing by leaps and bounds. So much so that computing is moving from desk to the pocket. As long as it remained on the desk, the issue of powering it wasn't an issue, as it used standard utility power. But with its move to the pocket, power has become a major concern. How many times has it happened that you're attending an important phone call on your cellphone, and its battery conks off? Or you're not able to use your digital camera on your camping trip because the battery drained out? You're finishing your presentation while waiting for your flight when the notebook's battery died. We've all faced one such situation at one time or the other. Currently, lithium ion or lithium polymer-based batteries are being used to power these mobile devices, and are proving to be insufficient. That's why an alternative power source, called micro fuel cells or MFCs, is being developed. Let's look at where it's reached, whether it'll be able to actually replace conventional batteries, and if yes, by when? 

Conventional lithium ion or polymer-based batteries have been in the market for a long time now. In fact, they first became a commercial reality way back in 1991, and the credit for it goes to Sony. Since then, the technology behind these batteries has seen some development. They've become more compact, lightweight and efficient. This development, however, is not sufficient to keep up with the pace of innovation in the mobile computing space. Portable devices are becoming more powerful and, therefore, more power hungry, staying right on track with the Moore's law that states that the computing power doubles every 18 months. Does this indicate that the conventional rechargeable batteries are nearing their end? If all the noise about micro fuel cells is true, then it might just happen. 

Micro fuel cells use chemical reaction to produce energy. While there are many different types of fuel cells, the ones that are slated to replace lithium ion batteries are the Direct Methanol Fuel Cells, or DMFCs. These combine methanol, water and air to produce electricity. Their benefits are plenty. For one, DMFCs offer a far higher energy potential, resulting in much longer battery life (as much as ten times) over the conventional batteries. They're more environment-friendly with water and heat being their byproducts. Moreover, to recharge them, you don't need to hunt for a power outlet, nor do you need to carry a separate power adapter with you. Instead, simply replacing or refilling the methanol cartridge does the job. So basically, fuel cell powered devices are completely free from AC power. Fuel cells are also free from the potential hazards that exist in the conventional batteries. For instance, a conventional battery can get damaged if there's a short circuit in the load, overload or if it gets over charged. Worse still, it can even damage the device it's powering. In case of fuel cells, none of these conditions will matter, because they don't 'store' but 'generate' energy through a chemical reaction. So while batteries loose energy over time, fuel cells don't. 

DMFCs are capable of providing up to 60 Volts, which is enough to power various portable computing devices. The major market for these will be the portables that require rechargeable batteries, such as pagers, cellphones, video recorders, camcorders, PDAs, notebooks and even portable power tools such as drills, saws and vacuum cleaners. Now the focus is on miniaturizing them to fit into devices like hearing aids, smoke detectors, burglar alarms, hotel locks and meter readers.



Well, all this doesn't mean that there is no flip side to fuel cells. It has a critical negative aspect that has nothing to do with technology, but legalities. There are issues with carrying fuel cells on airplanes and other public transport systems, since they contain hydrogen, methanol, etc. Currently, everybody's trying to build their own proprietary fuel cells. This will lead to non-standardization of equipment, which is
not healthy. 

So standards will have to be worked out for fuel-cell cartridges to make them compatible. It shouldn't happen that a fuel-cell cartridge from Hitachi doesn't fit into a fuel-cell from NEC. Since fuel-cell based devices will be completely free of AC power, fuel cell cartridges will have to be made readily available everywhere, just like a pack of dry cells. So whichever company introduces MFCs, it has to have a proper sales and distribution network in place. Lastly, the fuel cells will have to hit the

market at same price point as conventional batteries.

Many fuel cell prototypes have already been introduced, but currently, hardly any MFC-based portable computing devices are available commercially. Market research shows that these products will gain mass-market acceptance only by 2008, and by 2013, it will be an $11 billion market. Given the slow pace of development in conventional batteries, it's unlikely that they'll be able to compete with fuel cells by then. So until then,

enjoy using conventional batteries!

Anil Chopra, Associate Editor