1. Dalian Key Lab of Marine Micro/Nano Energy and Self‐powered Systems Marine Engineering College Dalian Maritime University Dalian 116026 China
2. College of Engineering Peking University Beijing 100871 China
3. State Key Laboratory of Tribology Department of Mechanical Engineering Tsinghua University Beijing 100084 China
4. School of Electronics and Information Technology Guangdong Ocean University Zhanjiang 524088 China
5. Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing 101400 P. R. China
6. School of Materials Science and Engineering Georgia Institute of Technology Atlanta GA 30332‐0245 USA