Big Charge For Nanobatteries

Gary W. Rubloff, Sang Bok Lee, and coworkers at the University of Maryland have devised a precisely controlled fabrication method to make a battery that actually consists of billions of nanobatteries connected in parallel (Nat. Nanotechnol. 2014, DOI: 10.1038/nnano.2014.247). Each individual nanobattery is made inside a nanopore of a ceramic template by atomic layer deposition of ruthenium charge collectors topped with vanadium oxide storage material. Pristine V₂O₅ at one end serves as the cathode, and lithiated V₂O₅ at the other end serves as the anode. The battery array achieves the predicted capacity for the V₂O₅ storage material and power levels that are 10-fold higher than previously reported nanostructured batteries, the researchers say. More than 80% of the initial capacity is retained after 1,000 charge-discharge cycles. The controlled geometry allows investigation of ion transport between electrodes less than 100 nm apart, comments Christopher P. Rhodes, a nanomaterials expert at Texas State University. “This is an important and largely unexplored area of research,” Rhodes says.