Cross-Linked PVA/HNT Composite Separator Enables Stable Lithium-Organic Batteries under Elevated Temperature

Abstract

Li-organic batteries (LOBs) are promising advanced battery systems because of their unique advantages in capacity, cost, and sustainability. However, the shuttling effect of soluble organic redox intermediates and the intrinsic dissolution of smallmolecular electrodes have hindered the practical application of these cells, especially under high operating temperatures. Herein, a cross-linked membrane with abundant negative charge for hightemperature LOBs is prepared via electrospinning of poly(vinyl alcohol) containing halloysite nanotubes (HNTs). The translocation of negatively charged organic intermediates can be suppressed by the electronic repulsion and the cross-linked network while the positively charged Li + are maintained, which is attributed to the intrinsic electronegativity of HNTs and their well-organized and homogeneous distribution in the PVA matrix. A battery using a PVA/HNT composite separator (EPH-10) and an anthraquinone (AQ) cathode exhibits a high initial discharge capacity of 231.6 mAh g −1 and an excellent cycling performance (91.4% capacity retention, 300 cycles) at 25 °C. Even at high temperatures (60 and 80 °C), its capacity retention is more than 89.2 and 80.4% after 100 cycles, respectively. Our approach demonstrates the potential of the EPH-10 composite membrane as a separator for high-temperature LOB applications.

Electrochemical Oxidation of Anthracene to Anthraquinone inside the Nanopores of Activated Carbon: Implications for Electrochemical Capacitors

“…AC/ANT does not show a redox peak in its voltammogram, while a distinct reversible peak couple is observed for AC/ANT-Ox between −0.2 and 0.05 V. It has been reported that AQ-adsorbed porous carbons show reversible redox peaks in the same potential range when using the same electrolyte, 21 whereas the redox potential depends on the kind of electrolytes. 22 Given the reversible redox peak potential of AC/ANT-Ox, ANT was expected to be transferred to AQ by electrochemical oxidation. Indeed, the shape of the voltammogram of AC/ANT-Ox is similar to that of AC/AQ, suggesting that the ANT in AC/ANT was electrochemically oxidized to AQ.…”

“…Therefore, the amounts of AC per 1 cm 3 of the electrodes can be regarded as the same for all the samples, and the current per 1 g of AC is correlated with the current per unit electrode volume (i.e., the volumetric current). AC/ANT does not show a redox peak in its voltammogram, while a distinct reversible peak couple is observed for AC/ANT-Ox between −0.2 and 0.05 V. It has been reported that AQ-adsorbed porous carbons show reversible redox peaks in the same potential range when using the same electrolyte, whereas the redox potential depends on the kind of electrolytes . Given the reversible redox peak potential of AC/ANT-Ox, ANT was expected to be transferred to AQ by electrochemical oxidation.…”

An electrospun three-layer nanofibrous membrane-based in situ gel separator for efficient lithium-organic batteries

“…S10, ESI†). 17,24 Overall, the electrochemical performance indicated that the PSE11-Gel separator is a good solution for fabricating high-performance and stable LOBs.…”

Crosslinked PVA/Citric Acid Nanofibrous Separators with Enhanced Mechanical and Thermal Properties for Lithium-Ion Batteries

“…For example, Fartash et al [26] prepared PAN/PVA/MA separators via electrospinning, using malonic acid (MA) as a crosslinking agent with enhanced tensile strength and reduced thermal shrinkage. In another research, Gong et al [27] fabricated the PVA/HNT composite separator via the electrospinning of PVA containing halloysite nanotubes (HNTs), followed by crosslinking via immersion in a glutaraldehyde dispersion. The PVA/HNT separator showed excellent thermal stability and mechanical properties due to the interlocking interconnections between the thermally resistant HNTs and the PVA matrix.…”