Oxocarbon Salts for Fast Rechargeable Batteries.
Oxocarbon salts (M2 (CO)n ) prepared through one-pot proton exchange reactions with different metal ions (M=Li, Na, K) and frameworks (n=4, 5, 6) have been rationally designed and used as electrodes in rechargeable Li, Na, and K-ion batteries. The results show that M2 (CO)5 /M2 (CO)6 salts can insert two or four metal ions reversibly, while M2 (CO)4 shows less electrochemical activity. Especially, we discover that the K2 C6 O6 electrode enables ultrafast potassium-ion insertion/extraction with 212 mA h g(-1) at 0.2 C and 164 mA h g(-1) at 10 C. This behavior can be ascribed to the natural semiconductor property of K2 C6 O6 with a narrow band gap close to 0.9 eV, the high ionic conductivity of the K-ion electrolyte, and the facilitated K-ion diffusion process. Moreover, a first example of a K-ion battery with a rocking-chair reaction mechanism of K2 C6 O6 as cathode and K4 C6 O6 as anode is introduced, displaying an operation voltage of 1.1 V and an energy density of 35 Wh kg(-1) . This work provides an interesting strategy for constructing rapid K-ion batteries with renewable and abundant potassium materials.
Key Laboratory of Advanced Energy Materials Chemistry and State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China.
Qing
Q
Zhao
Key Laboratory of Advanced Energy Materials Chemistry and State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China.
Jianbin
J
Wang
Key Laboratory of Advanced Energy Materials Chemistry and State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China.
Yong
Y
Lu
Key Laboratory of Advanced Energy Materials Chemistry and State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China.
Yixin
Y
Li
Key Laboratory of Advanced Energy Materials Chemistry and State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China.
Guangxin
G
Liang
Key Laboratory of Advanced Energy Materials Chemistry and State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China. chenabc@nankai.edu.cn.|Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China. chenabc@nankai.edu.cn.
Jun
J
Chen
batteries; electrodes; molecular engineering; renewable materials; sustainable chemistry