Graphene Acid for Lithium‐Ion Batteries—Carboxylation Boosts Storage Capacity in Graphene. Issue 5 (22nd December 2021)

• Record Type: Journal Article
• Authors: Obraztsov, Ievgen; Bakandritsos, Aristides; Šedajová, Veronika; Langer, Rostislav; Jakubec, Petr; Zoppellaro, Giorgio; Pykal, Martin; Presser, Volker; Otyepka, Michal; Zbořil, Radek
• Is Part Of: Advanced energy materials. Volume 12:Issue 5(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-22
• Subjects: carboxylation -- graphene acid -- lithium‐ion batteries -- organic anodes; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202103010
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Environmentally sustainable, low‐cost, flexible, and lightweight energy storage technologies require advancement in materials design in order to obtain more efficient organic metal‐ion batteries. Synthetically tailored organic molecules, which react reversibly with lithium, may address the need for cost‐effective and eco‐friendly anodes used for organic/lithium battery technologies. Among them, carboxylic group‐bearing molecules act as high‐energy content anodes. Although organic molecules offer rich chemistry, allowing a high content of carboxyl groups to be installed on aromatic rings, they suffer from low conductivity and leakage to the electrolytes, which restricts their actual capacity, the charging/discharging rate, and eventually their application potential. Here, a densely carboxylated but conducting graphene derivative (graphene acid (GA)) is designed to circumvent these critical limitations, enabling effective operation without compromising the mechanical or chemical stability of the electrode. Experiments including operando Raman measurements and theoretical calculations reveal the excellent charge transport, redox activity, and lithium intercalation properties of the GA anode at the single‐layer level, outperforming all reported organic anodes, including commercial monolayer graphene and graphene nanoplatelets. The practical capacity and rate capability of 800 mAh g −1 at 0.05 A g −1 and 174 mAh g −1 at 2.0 A g −1 demonstrate the true potential of GA anodes in advanced lithium‐ion batteries. Abstract : Densely carboxylated graphene integrates the benefits of small organic carboxylated molecules and graphene to coordinate and store Li effectively through both diffusion‐ and surface‐controlled mechanisms. Spacer‑free carboxyl groups attached to graphene promote electronic communication allowing flawless operation even at high rates, with 90% active material content.