The trick is finding a polymer anode suitable for a workable battery. When used in a battery, certain polymers can act as great cathodes, readily accepting electrons coming from the anode through an external circuit. On the other hand, for a conducting polymer to act as an anode, it must be doped so that an extra electron is forced into the polymer backbone, giving it a negative charge. Unlike doped cathodes, however, doped anodes are unstable and vulnerable to moisture.
Despite the challenge, the Johns Hopkins team charged ahead. Eventually they found that by entrapping a lithium ion in the polymer chain they could make a type of plastic called polypyrrole behave as an anode. After three years of effort, Poehler felt that this system “started to look decent.” By the summer of 1995, the lab produced a working battery. But the battery produced only about one volt per cell-far too low for many applications-and it still required lithium as a dopant.
The team went back to the drawing board. This time they made a significant breakthrough in a little more than six months. The Johns Hopkins team turned to a family of polymers called fluorophenylthiophenes to form the electrodes; one member of the family, 3,4,5 TFPT, acts as the anode, while another, 3,5 DFPT, as the cathode. The polymers were then sandwiched around a battery electrolyte made from a thin polyacylonitrile gel. The battery could produce three volts of electricity per cell and be recharged hundreds of times.
It was a remarkable breakthrough. The batteries are as flexible as plastic wrap-so they can be rolled into the cylindrical shape of a conventional flashlight battery, or used as credit-card-thin sheets. Unlike conventional batteries, which often do not work at temperatures much below freezing, they are capable of working at temperatures as low as -40 degrees C. As an extra bonus, the batteries change colors when they discharge, making it easy to tell when a recharge is needed.
Now the lab had a workable prototype, but it was only the starting point on the hard road to commercialization. Poehler, who has seen lots of technology transfer deals in his capacity as vice provost, took the lead in the team’s business effort. “The first challenge is to determine if the technology is competitive,” he explains. By late 1996, when the story broke in the media, the Johns Hopkins researchers were confident that their battery had reached that stage. They sorted through the deluge of requests and met with more than 40 potential research partners or funders, going on visits or being visited by companies or research groups almost every week for more than a year.
“We did not look at most of the meetings as opportunities to do business deals, but as chances to exchange information,” Poehler says. Yet the overarching goal was to make a major deal that would bring the battery to the market, not just bring in money to do further research. “We are still working on this, and are always struggling to get to the point where the technology sells itself,” he says.
Getting to that point, however, isn’t easy. In fact, it means negotiating a complex world of venture capital and corporate financing. Poehler and Searson each have impressive academic reputations, but, like most scientists, neither has much experience in business wheeling and dealing and the world of high finance.