MgO‐Template Synthesis of Extremely High Capacity Hard Carbon for Na‐Ion Battery

• Published in: Angewandte Chemie International Edition 2021-03, Vol.60 (10), p.5114-5120
• Main Authors: Kamiyama, Azusa, Kubota, Kei, Igarashi, Daisuke, Youn, Yong, Tateyama, Yoshitaka, Ando, Hideka, Gotoh, Kazuma, Komaba, Shinichi
• Format: Article
• Language: English
• Subjects: Acid leaching; Carbon; Communication; Communications; Electrochemistry; hard carbon; Leaching; Magnesium; Magnesium oxide; microporous materials; Rechargeable batteries; Sodium; sodium storage; Sodium-ion batteries; template synthesis
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202013951

Extremely high capacity hard carbon for Na‐ion battery, delivering 478 mAh g−1, is successfully synthesized by heating a freeze‐dried mixture of magnesium gluconate and glucose by a MgO‐template technique. Influences of synthetic conditions and nano‐structures on electrochemical Na storage properties in the hard carbon are systematically studied to maximize the reversible capacity. Nano‐sized MgO particles are formed in a carbon matrix prepared by pre‐treatment of the mixture at 600 °C. Through acid leaching of MgO and carbonization at 1500 °C, resultant hard carbon demonstrates an extraordinarily large reversible capacity of 478 mAh g−1 with a high Coulombic efficiency of 88 % at the first cycle. Mg‐templated hard carbon as an extremely high capacity negative electrode material for Na‐ion batteries is successfully synthesized by heating a freeze‐dried mixture of magnesium gluconate and glucose. The hard carbon demonstrates an extraordinarily large reversible capacity of 478 mAh g−1 with a high Coulombic efficiency of 88 % at the first cycle. Owing to the low potential operation, estimated energy density of the full cell is very high.