6th workshop for battery exploratory development: Williamsburg, VA June 21-24, 1999--part I

Advanced Battery Technology, Sep 1999 by Coffey, Brendan

About 140 attendees were at this forum, which was sponsored by the Office of Naval Research (ONR) and coordinated by the High Energy Battery R&D Group of the Naval Surface Warfare Center (NSWC). The workshop format allowed for good exchange between attendees.

Dave Sudduth, who heads the Navy's Applied Material Sciences Department, presented a "waterfall" chart showing how, over the past 50 years, the Navy development/qualifications efforts have successfully moved numerous technologies from the basic research classification (6.1-6.2), through development (6.3-6.4), to fleet use (6.5). The chart showed how the activity and pace of development have increased steadily.

Brian Barnett (Arthur D. Little) gave the keynote address on the daunting topic of Batteries for the Next Millennium and wisely elected not to try and forecast past the first 100 years. Reviewing battery technologies that have emerged in the current century, Barnett pointed out how significant advances in battery technologies have always been led by emerging electronic products. One current trend is a move from electromechanical toward fully electronic devices; for example, the MP3 audio player. Barnett believes that the persistent drive for a broadband, anywhere/ anytime information distribution system could lead to the creation of an analogous power distribution system. Rather than attempting to continually extend device operating time by developing ever-higher energy batteries, users might tap into a network to recharge metered energy. This would drive technology development in the direction of fast-charge systems and supercapacitors. Barnett concludes there is still much untapped potential in lithium-ion technology and it will continue to be a major technology platform for the early part of the next century. As he has stated before, Barnett believes the development cycle for an entirely new battery technology is 15-20 years. To maintain even this pace of development, better tools are required. Methods, including design of experiments, molecular modeling, and accelerated predictive tests, must be advanced to fully evaluate increasingly complex materials and process interactions.

Following the keynote address, representatives of the various Department of Defense agencies outlined their technology requirements and program objectives. These presentations helped put into context the subsequent papers by contractors carrying out funded development.

Richard Carlin (ONR) presented an overview of the Navy's fundamental research into electrochemical power, both batteries and fuel cells. Major program areas are materials and nano-components. The materials programs mainly relate to high-energy actives for the rechargeable lithium systems that the Navy believes will eventually replace silver/zinc. The Navy is pursuing a program to develop 3-D nano-architectures for future electrochemical power sources. The goal is to develop ways to synthesize nanoscale quantized energy storage and molecular electronics components for high-speed, high-density devices.

Patricia Smith (NSWC) described some Navy applications driving current development efforts. Modern sonobouys and undersea surveillance systems require combinations of energy and power that push the envelope of the Ragonne plot. Navy development is addressing these needs with two parallel approaches. The first is to increase the power available from high-energy primary Li/SO2 batteries through redesigns that yield extremely low internal resistance. The second route is to increase the discharge period of high-rate thermal batteries (from 2 to 6 hours) through cell designs with improved thermal management. For undersea vehicles, the Navy is seeking extremely high-energy rechargeables for which they are willing to trade off cycle life. A target is 400Wh kg-1 for 50 cycles. Jim Barnes (NSWC) described the Navy's Battery Qualifications, Safety and other Support programs.

The U.S. Army has established the Power Sources Center of Excellence (PSCOE), which integrates research through logistics functions to provide the most power-efficient solutions for the least weight and cost. Robert Hamlen (U.S. Army CECOM) noted the Center's mission includes not only batteries, but also the entire spectrum of power technology, including fuel cells, generators, and solar power. Until recently the Army used primary batteries almost exclusively in the field, but budget considerations have led to an increasing use of rechargeables. This presents new challenges related to reliable field recharging. Army electronics equipment can consume several times the power of its civilian equivalent. For example, the backbone of Army field communications, SINGARS radio, operates without cell sites and requires strong encryption. These heavy power demands could consume a high-energy primary battery in two or three days. The PSCOE now takes a systems-architecture approach to power management for all field equipment. The overall system can be designed to minimize power needs, incorporating automated regulation and conservation of energy usage through low power electronics, software, and more efficient communications protocols.