Number 215 (Story #3), February 24, 1995 by Phillip F. Schewe and Ben Stein THE DEVELOPMENT OF LIGHTER BATTERIES would please anyone who drives an electric car or uses a laptop computer. Heretofore the battery type with the best gravimetric energy density (stored energy per battery weight) is one that uses a lithium cathode and a lithium compound anode. A new lithium battery developed at Tokyo University uses a lithium metal anode and a cathode consisting of a composite of two organic materials (dimercaptan and polyanilene). At peak performance the organic-cathode battery had an energy density of more than 600 Watt-hours per kg, compared to an equivalent density of about 400 for the most sophisticated commercially available lithium battery, one using a LiCoO2 cathode. The new battery retained 80-90% of its original energy storage capacity even after 100 recharging cycles. (N. Oyama et al., Nature, 16 February 1995.)