Stable Na Electrodeposition Enabled by Agarose-Based Water-Soluble Sodium Ion Battery Separators
Open access
Date
2021-05-12Type
- Journal Article
Abstract
Developing efficient energy storage technologies is at the core of current strategies toward a decarbonized society. Energy storage systems based on renewable, nontoxic, and degradable materials represent a circular economy approach to address the environmental pollution issues associated with conventional batteries, that is, resource depletion and inadequate disposal. Here we tap into that prospect using a marine biopolymer together with a water-soluble polymer to develop sodium ion battery (NIB) separators. Mesoporous membranes comprising agarose, an algae-derived polysaccharide, and poly(vinyl alcohol) are synthesized via nonsolvent-induced phase separation. Obtained membranes outperform conventional nondegradable NIB separators in terms of thermal stability, electrolyte wettability, and Na+ conductivity. Thanks to the good interfacial adhesion with metallic Na promoted by the hydroxyl and ether functional groups of agarose, the separators enable a stable and homogeneous Na deposition with limited dendrite growth. As a result, membranes can operate at 200 μA cm–2, in contrast with Celgard and glass microfiber, which short circuit at 50 and 100 μA cm–2, respectively. When evaluated in Na3V2(PO4)3/Na half-cells, agarose-based separators deliver 108 mA h g–1 after 50 cycles at C/10, together with a remarkable rate capability. This work opens up new possibilities for the use of water-degradable separators, reducing the environmental burdens arising from the uncontrolled accumulation of electronic waste in marine or land environments. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000485189Publication status
publishedExternal links
Journal / series
ACS Applied Materials & InterfacesVolume
Pages / Article No.
Publisher
American Chemical SocietySubject
Agarose; Degradability; Sodium ion battery (NIB); Sodium plating/stripping; Battery life span; Circular economyOrganisational unit
03763 - Niederberger, Markus / Niederberger, Markus
Funding
ETH-45 18-1 - Development of transient lithium ion batteries (ETHZ)
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