1. Department of NanoEngineering University of California San Diego San Diego CA 92093 USA
2. Key Laboratory of Biometallurgy of Ministry of Education, School of Mineral Processing and Bioengineering Central South University Changsha 410083 China
3. Department of Physics and Astronomy University of California Irvine CA 92697 USA
4. Department of Chemical Engineering Stanford University Stanford CA 94305 USA
5. Program of Chemical Engineering University of California San Diego CA 92093 USA
6. Program of Materials Science University of California San Diego CA 92093 USA
7. Sustainable Power and Energy Center University of California San Diego CA 92093 USA