A nanostructure on Cu comprising a plurality of Cu(OH).sub.2 nanofibers wherein the nanofibers are formed by treating the Cu surface with ammonia solution to produce a layer of malachite on the Cu surface and treating the malachite coated Cu with NaOH aqueous solution to convert the malachite layer on the Cu surface into Cu(OH).sub.2 nanofibers. The nanostructure may be formed on a Cu thin film. The thin film may be a layer of a laminated lithium ion battery.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under Contract No. DE-AC02-05CH11231 awarded by the United States Department of Energy to The Regents of the University of California for management and operation of the Lawrence Berkeley National Laboratory. The government has certain rights in this invention.