Porous-carbon aerogels with tailored subnanopores for high cycling stability and rate capability potassium ion battery anodes

• Published in: ACS applied materials & interfaces
• Main Authors: Zhao, Wenqi, Shen, Yupeng, Zhang, Hui, Wang, Yunsong, Wu, Yizeng, Wu, Huaisheng, Zou, Mingchu, Wang, Qian, Li, Yibin, Cao, Anyuan
• Format: Journal Article
• Language: English
• Published: United States 20-05-2020
• EISSN: 1944-8252

Developing advanced electrode materials for potassium ion batteries (PIBs) is an emerging research area in recent years; so far, several strategies such as heteroatom doping to carbon, increasing interlayer spacing or creating amorphous region in graphite have been investigated. Here, we studied the effect of subnanopores in a porous-carbon aerogel with a centered pore size distribution at around 0.8 nm and achieved outstanding PIB performance including long cycling stability (particularly at small current densities for prolonged charge/discharge period) and high rate capability with enhanced retentions. Mechanism studies reveal very high contribution from surface capacitive potassium (K)-ion storage (more than 90%) to the total capacity, and theoretical calculations show that 0.8 nm subnanopores lead to substantially low barrier for K-ion transport and storage, with ultrasmall diffusion energy and negligible lattice change. Subnanopore engineering as demonstrated here may be adopted to develop highly efficient and stable porous-carbon-based structures for applications in advanced energy storage systems and electrochemical catalysis.