1. The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
2. Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
3. Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York 14853, USA
4. Institute of Materials Research and Engineering, Agency for Science Technology and Research, #08-03, 2 Fusionopolis Way, Singapore 138634