Binder and conductive diluents free NaVPO4F based free-standing positive electrodes for sodium-ion batteries

Kumar, V. Kiran and Ghosh, Sourav and Naresh, Vangapally and Ummethala, Govind and Malladi, Sairam K and Martha, Surendra Kumar (2022) Binder and conductive diluents free NaVPO4F based free-standing positive electrodes for sodium-ion batteries. Journal of The Electrochemical Society, 169 (1). ISSN 0013-4651

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Abstract

Herein, we report a carbon-fiber-based freestanding electrode for NaVPO4F cathodes in sodium-ion batteries. The replacement of conventional aluminium foil with a carbon fiber mat-based current collector results in significant improvement in capacity at high rates and charge-discharge cycle stability. Petroleum-pitch (P-Pitch) has dual functions. P-pitch is used as a binder to bind NaVPO4F particles onto the carbon fiber mat, which helps to eliminate typical organic binders. At the same time, P-Pitch acts as a conducting precursor to coat onto NaVPO4F particles. The amount of P-pitch required to achieve stable electrochemical performance is optimized. As a result, 15 and 20% of P-pitch in the composite NaVPO4F electrodes (15P_NVPF@CF and 20P_NVPF@CF) shows stable electrochemical performances. A reversible capacity of 120 and 119 mAh g-1 is observed for 15P_NVPF@CF and 20P_NVPF@CF, with 97 and 98% retention in capacity after 300 cycles, respectively. Further, at a 0.5 C current rate, 15P_NVPF@CF and 20P_NVPF@CF electrodes show 86 and 87% capacity retention after 1000 cycles. The significant electrochemical performance of these freestanding electrodes is ascribed to the interlinked carbon matrix with NaVPO4F particles and carbon-fiber mat, which provides a continuous path for electronic conduction and faster kinetics of NaVPO4F particles. © 2022 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.

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IITH Creators:

IITH Creators	ORCiD
Malladi, Sairam K	UNSPECIFIED
Martha, Surendra Kumar	https://orcid.org/0000-0002-7762-7237

Item Type:

Article

Uncontrolled Keywords:

A-carbon; Current-collector; Electrochemical performance; Fibermat; Free standings; Free-standing electrode; High charges; High rate discharges; Petroleum pitch; Positive electrodes

Subjects:

Others > Metallurgy Metallurgical Engineering
Chemistry
Materials Engineering > Materials engineering

Divisions:

Department of Chemistry
Department of Material Science Engineering

Depositing User:

. LibTrainee 2021

Date Deposited:

26 Jul 2022 04:35

Last Modified:

26 Jul 2022 04:35

URI:

http://raiithold.iith.ac.in/id/eprint/9923