Controlled Growth of Nanostructured Biotemplates with Cobalt and Nitrogen Codoping as a Binderless Lithium-Ion Battery Anode

• Published in: ACS applied materials & interfaces Vol. 8; no. 40; pp. 26868 - 26877
• Main Authors: Huggins, Tyler M, Whiteley, Justin M, Love, Corey T, Lee, Kwangwon, Lee, Se-Hee, Ren, Zhiyong Jason, Biffinger, Justin C
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 12.10.2016
• Subjects: biotemplate; lithium; filamentous fungi; cobalt; nitrate
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.6b09300

Biomass can serve as a sustainable template for the synthesis of carbon materials but is limited by the intrinsic properties of the precursor organism. In this study we demonstrate that the properties of a fungal biotemplate can be tuned during cultivation, establishing a new electrode manufacturing process and ultimately improving the electrochemical performance of the biomass-derived electrode. More specifically, the carbon/nitrogen ratio of Neurospora crassa mycelia mats was shifted by 5-fold while generating cobalt nanoparticles into the hyphal structure originating from macroconidia spores. This shift was achieved through nitrate limitation and equal molar concentrations of Mg2+ and Co2+ in the growth media. The resulting mycelia mat was converted via a high-temperature pyrolysis process (800 °C) to produce a freestanding cobalt and nitrogen codoped electrode material with no postmodification. Ultimately, nitrogen doping resulted in one of the highest recorded specific reversible capacity for a freestanding biomass-derived lithium-ion anode (400 mAh g–1 at C/10). We observed an additional improvement in capacity to 425 mAh g–1 with the incorporation of 3 wt % Co. Our results show how shaping the chemical characteristics of an electrode during the growth of the biotemplate allows for sustainable carbon-based material manufacturing from a living (self-assembled) material.