# Pectin Extracted by a Recyclable Molecular Mixture: A Promising Material for Porous Membranes in Quasi-Solid-State Na-Ion Batteries

## TL;DR

Researchers extracted pectin from apple waste using a recyclable solvent and used it to create efficient membranes for sodium-ion batteries.

## Contribution

A recyclable molecular mixture was developed for pectin extraction, enabling the creation of high-performance quasi-solid-state Na-ion battery membranes.

## Key findings

- Pectin extracted using [DMBA][OAc] and ethanol was effective for battery membranes.
- Optimized extraction conditions yielded 9.6 wt% pectin with high purity.
- The battery half-cell showed a capacity of ∼130 mAh g–1 at C/20.

## Abstract

In this work, we explored a solvent-based extraction
of pectin
from apple pomace and evaluated the extracted pectin as a precursor
for porous quasi-solid-state Na-ion battery membranes, alongside testing
hard carbon derived from commercial pectin as an electrode material.
A screening of 10 distinct ionic liquids (ILs) and 6 different antisolvents
revealed that N,N-dimethylbutylammonium
acetate ([DMBA]­[OAc]), combined with ethanol, was highly effective
in pectin extraction, while the same IL with 1-butanol as antisolvent
yielded a purer form of the pectin product. Additionally, [DMBA]­[OAc]
did not behave as an IL and resembled a molecular mixture based on 1H NMR and conductivity measurements. A two-level fractional
design was employed with four factors, considering temperature, solid
loading, acid-to-base ratio (ABR), and water content of ILs, where
temperature and solid loading were significant factors. The optimized
conditions for the pectin extraction were at 80 °C, 1 h, with
15 wt % of solids loading, an ABR of 1.1, and 30 wt % of water content
(IL), which yielded 9.6 wt % of pectin. The resulting quasi-solid-state
Na-ion half-cell exhibited a capacity of ∼130 mAh g–1 at C/20, making it an excellent candidate for energy storage applications.