N/O double-doped biomass hard carbon material realizes fast and stable potassium ion storage

• Published in: Carbon (New York) Vol. 176; pp. 71 - 82
• Main Authors: Yang, Mengmeng, Kong, Qingquan, Feng, Wei, Yao, Weitang
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.05.2021; Elsevier BV
• Subjects: Anode; Anodes; Batteries; Biomass; Cages; Carbon; Chemical synthesis; Density functional theory; DFT; Doping; Electrochemical analysis; Electrode materials; Ganoderma lucidum spore; Hydrothermal reactions; Ion storage; Lithium; Nitrogen and oxygen dual-doped; Potassium; Potassium ion battery; Ganoderma lucidum spore; DFT; Anode; Nitrogen and oxygen dual-doped; Potassium ion battery
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2021.01.114

In this study, N/O co-doped cage-type biomass carbon (NOBC) was prepared through a simple and facile hydrothermal reaction and two-step carbonization method. As the anode of a potassium ion battery, NOBC displays a superhigh long-cycling performance and a super high rate performance. NOBC-2 provides an excellent reversible capacity of 251.2 mAh g−1 after 1500 cycles at 0.5 A g−1, and an excellent performance of 334.6 mAh g−1 at a high current density of 5 A g−1 (after 2000 cycles). The reversible capacity of 124.19 mAh g−1 can be maintained even after 5000 cycles at 10 A g−1. The excellent performance of NOBC is attributed to the unique hollow cage structure, internal 3D carbon network structure and N/O co-doping. Based on the results of detailed fundamental analysis, the pseudo-capacitance mechanism contributes to the higher K ion storage process in NOBC-2. Density functional theory (DFT) calculations further show that N/O double doping can promote the adsorption of K ions in biomass carbon materials and improve the conductivity of the materials. The simple synthesis route and excellent electrochemical performance provide new insights for the search for novel carbon-based K storage anode materials with high energy and long cycle life. The N/O co-doped biomass carbon material (NOBC-2) is synthesized through a simple hydrothermal reaction and two-step carbonization, and exhibits surprisingly high energy and long cycle life stability in the potassium ion half-cell. [Display omitted] •The preparation method of N/O co-doped biomass carbon material (NOBC-2) is simple and convenient.There are wide sources of biomass raw materials, and mass production is expected.•There are wide sources of biomass raw materials, and mass production is expected.•NOBC-2 exhibits surprisingly high energy and long cycle life in potassium ion half-cells.•Mechanism studies are designed to investigate the K+ storage behaviors.