1. Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
2. Materials Department, University of California, Santa Barbara, California 93106, United States
3. Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
4. Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575 Singapore
5. Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore