1. Researchers at Japan’s National Institute of Advanced Industrial Science and Technology (AIST) have developed a prototype of a battery that can simultaneously offer the high cell voltage of Li-ion cells and the large cell capacity of Ni-MH cells: a rechargeable nickel (cathode) / lithium metal (anode) battery using a hybrid aqueous and organic electrolyte separated by a superionic conductor glass ceramic film.
A rechargeable Ni-Li battery, in which nickel hydroxide serving as a cathode in an aqueous electrolyte and Li metal serving as an anode in an organic electrolyte were integrated by a superionic conductor glass ceramic film (LISICON), was proposed with the expectation to combine the advantages of both a Li-ion battery and Ni-MH battery. It has the potential for an ultrahigh theoretical energy density of 935 Wh/kg, twice that of a Li-ion battery (414 Wh/kg), based on the active material in electrodes. A prototype Ni-Li battery fabricated in the present work demonstrated a cell voltage of 3.47 V and a capacity of 264 mAh/g with good retention during 50 cycles of charge/discharge. This battery system with a hybrid electrolyte provides a new avenue for the best combination of electrode/electrolyte/electrode to fulfill the potential of high energy density as well as high power density.
A paper on the proposed Ni-Li system was published 5 October in the Journal of the American Chemical Society.
2. The Battery 500 Project recently held its kickoff meeting at IBM’s Almaden Laboratory in San Jose, Calif., where leading scientists, engineers and other experts brainstormed about how to perfect the power source for all-electric automobiles.
In order to make 500 miles on a single battery charge possible, IBM is tracking toward an energy density of 1500 to 2000 watt hours per kilogram
IBM plans to harness its nanoscale semiconductor manufacturing techniques to boost the capacity of batteries by increasing their storage density by 10 times over the lithium-ion batteries used today. The Battery 500 Project aims to achieve that goal with a lithium-air battery technology, whose feasibility was demonstrated earlier this year at the University of St. Andrews in Scotland.
Lithium-air batteries are unique in that instead of being a sealed system, they couple to atmospheric oxygen—essentially harnessing the oxygen in the air as the cathode of the battery. Since oxygen enters the battery on-demand, it offers an essentially unlimited amount of reactant, metered only by the surface area of its electrodes. IBM believes its nanoscale semiconductor fabrication techniques can increase the surface area of the lithium-air battery’s electrodes by at least 100 times, enabling them to meet the goals of the project.
SJ Visco, E Nimon, LC De Jonghe, PolyPlus Battery Company, Berkeley, CA, USA, and Lawrence Berkeley National Laboratory, Berkeley,USA
Elsevier B.V. All rights reserved.
The large free energy for the reaction of lithium with oxygen has attracted the interest of battery researchers for decades. At a nominal potential of about 3V, the theoretical specific energy for a lithium/air battery is over 5000 Wh kg-1 for the reaction forming LiOH (Li + 1/4O2 + 1/2 H2O ↔ LiOH) and 11,000 Wh kg-1 for the reaction forming Li2O2 (2 Li + O2 ↔ Li2O2) or for the reaction of lithium with dissolved oxygen in seawater, rivaling the energy density for hydrocarbon fuel cells and far exceeding Liion battery chemistry that has a theoretical specific energy of about 400 Wh kg-1.