Tin‐Containing Graphite for Sodium‐Ion Batteries and Hybrid Capacitors. Issue 1 (30th September 2020)

• Record Type: Journal Article
• Authors: Palaniselvam, Thangavelu; Babu, Binson; Moon, Hyein; Hasa, Ivana; Santhosha, Aggunda L.; Goktas, Mustafa; Sun, Ya‐Nan; Zhao, Li; Han, Bao‐Hang; Passerini, Stefano; Balducci, Andrea; Adelhelm, Philipp
• Is Part Of: Batteries & supercaps. Volume 4:Issue 1(2021)
• Page Start: 173
• Page End: 182
• Publication Date: 2020-09-30
• Subjects: sodium-ion battery, anode, graphite, tin, hybrid capacitor; Electrochemistry -- Periodicals; Electrodes -- Periodicals; Electric batteries -- Periodicals; 621.31242
• DOI: 10.1002/batt.202000196
• Languages: English
• ISSNs: 2566-6223

Abstract

Abstract: The limited Na‐storage capacity of graphite anodes for sodium‐ion batteries (∼110 mAh g −1 ) is significantly enhanced by the incorporation of nanosized Sn (17 wt%). The composite (SntGraphite), prepared by simple annealing of graphite with SnCl2, shows a specific capacity of 223 mAh g −1 (at 50 mA g −1 ) combined with excellent cycle life (i. e., 96 % of capacity retention after 2, 200 cycles at 1 A g −1 ) and initial Coulomb efficiency (90 %). The combined storage of sodium in graphite (by solvent co‐intercalation) and Sn (by alloy formation) is followed by in situ X‐ray diffraction and in situ electrochemical dilatometry (ECD). While the additional tin almost doubles the electrode capacity, its contribution to the electrode expansion (∼3 %) is surprisingly small. The use of SntGraphite as anode for sodium‐ion hybrid capacitors with activated carbon as cathode provides a maximum energy and power density of ∼93 Wh kg −1 and 7.8 kW kg −1, with a capacity retention of ∼80 % after 8, 000 cycles. Abstract : Dual purpose : The capacity of graphite electrodes for Na‐ion batteries is doubled by adding nanosized tin (17 wt%). The material shows excellent cycle life and rate capability, which makes it also suitable as electrode for Na‐ion hybrid capacitors. During cycling, a combined storage based on solvent co‐intercalation (graphite) and alloy formation (Sn) takes place. The electrode reaction if followed in situ by XRD and electrochemical dilatometry.