Batteries & Supercaps最新文献

The emerging concept of weakly solvating electrolytes in multivalent ion aqueous batteries has garnered attention due to their enhanced kinetic performance at a low cost. This article aims to dissect the concept of “weakly solvating electrolyte” into three revelations, i. e., ion solvation, hydrogen bonding strength, and ionic interactions. It is revealed that a weakly interacting solvent must satisfy the requirements of having a solvation strength weaker than water molecules, as well as disrupting rather than strengthening hydrogen bonding within them. Moreover, electrolyte chemistry requires balancing multiple factors, and one weakly interacting solvent can exhibit varying effects with different anions of zinc salts. This study offers quantitative descriptors to the concept of weak solvation, particularly for aqueous electrolytes, and provides insights for future electrolyte advancements for multivalent ion batteries.

Multielectron transfer in halogen batteries is a promising solution in pursuing high-energy-density and affordable energy storage systems. Interest in rich chemistries derived from unique valence electron structures of halogens is surging in electrode material design. However, deploying multielectron transfer chemistry comes with challenges, including limited redox reactivity and degrees of electrochemical irreversibility, which contribute to poor charging and cycling. To address these challenges, researchers explore physical/chemical strategies to activate high valence reactions and more electron transfer numbers and fix unstable valence state species through electrolyte and electrode regulation. This Concept presents the basic understanding of multielectron transfer electrochemistry concerning theoretical energy capabilities and electronic configuration evolutions. We divide multielectron transfer into two types: single and multi-redox centers, providing an overview of the current development of multielectron transfer and hoping it will spur more intensive efforts towards a diverse energy future.

This study explores the potential of re-purposing end-of-life commercial supercapacitors as electrochemical desalination cells, aligning with circular economy principles. A commercial 500-Farad supercapacitor was disassembled, and its carbon electrodes underwent various degrees of modification. The most straightforward modification involved NaOH-etching of the aluminum current collector to produce free-standing carbon films. More advanced modifications included CO₂ activation and binder-added wet processing of the electrodes. When evaluated as electrodes for electrochemical desalination via capacitive deionization of low-salinity (20 mM) NaCl solutions, the minimally modified NaOH-etched carbon electrodes achieved an average desalination capacity of 5.8 mg g⁻¹ and a charge efficiency of 80 %. In contrast, the CO₂-activated, wet-processed electrodes demonstrated an improved desalination capacity of 7.9 mg g⁻¹ and a charge efficiency above 90 % with stable performance over 20 cycles. These findings highlight the feasibility and effectiveness of recycling supercapacitors for sustainable water desalination applications, offering a promising avenue for resource recovery and re-purposing in pursuing environmental sustainability.

The current research explores the potential of carbon xerogel as a conductive filler in bipolar plates. The composites comprise graphite as the primary conductive filler and polypropylene as the binder. Carbon xerogel is introduced as a minor conductive filler, and its performance is compared with commercial carbon black. Both nanocarbons exhibit resemblances in microstructure, texture, and surface carbon chemistry. Through-plane conductivity measurements reveal enhanced electrical conductivity upon replacing a fraction of graphite with either nanofiller. Cross-sectional analyses of the plates employing computed tomography based on X-ray diffraction and phase contrasts indicate that the observed electrical conductivity difference stems from reduced trapped air during production and the distribution of the minor filler particles. Given the similarities between carbon xerogel and the reference nanofiller, this study introduces the innovative concept of employing carbon xerogel as a filler for conductive bipolar plates.

In this work, a new polymer has been explored as a cathode host for lithium-sulfur batteries (LSBs). Sulfurized polybutadiene materials were synthesized by a single-step, scalable, and easily tailored heat treatment method. The optimized synthesis process allows for high sulfur loadings of up to 50 wt %. Thermogravimetric analysis-mass spectrometry (TGA-MS) and X-ray photoelectron spectroscopy (XPS) studies confirm that the sulfur is covalently bound to the polymeric backbone, which overcomes the otherwise common capacity-fading polysulfide shuttle effect of lithium-sulfur (LSBs) batteries. The absence of free elemental sulfur in the synthesized active materials allows for a stable capacity of up to 1200 mAh g⁻¹ at a rate of C/20. The porous polymer networks reduce the pulverization of the cathode during cycling, resulting in long-term cycling stability of 1500 continuous galvanostatic charge/discharge (GCD) cycles. Capacity contribution studies depict that at a scan rate of 1 mV s⁻¹, the sulfurized polybutadiene cathode-based cells have 65 % capacitive and 35 % diffusive contribution of the total charge stored. A comprehensive study on Li-ion storage with capacity contribution and diffusion studies of polysulfide shuttle-free sulfurized polybutadiene cathode material for LSBs is presented.

Storage studies of lithium-ion battery electrolyte within bags made of commercial pouch foils, commonly used as encasing material of battery cells, revealed the presence of contamination leaching from the pouch foil material into the electrolyte. By analyzing the stored electrolyte via GC-MS the appearing compound was identified as 2,4-di-tert-butylphenol (2,4-DTBP). To investigate the influence of DTBP on the battery cell performance, full cells employing commercial LiNi_1/3Mn_1/3Co_1/3O₂ based cathodes and graphite-type anodes were assembled using 1 M LiPF₆ in ethylene carbonate/ dimethyl carbonate mixture as the electrolyte with/out the intentional addition of either 2,4-DTBP or its constitutional isomer 2,6-DTBP. Furthermore, dimethyl terephthalate (DMT), a literature known redox shuttle triggering impurity leaching from PET-based fixing tape used in LIBs, was added to compare the effect of DMT to DTBPs. It was revealed that either DTBP contaminations have a significant impact on the self-discharge behavior of the studied cells, which exceed the effect of present DMT. Moreover, all contaminants heavily increase transition metal dissolution-migration-deposition (TM DMD) processes and irreversible capacity loss. When vinylene carbonate, an SEI forming additive, is added to the electrolyte mixtures self-discharge, as well as TM DMD are suppressed to a different degree depending on the type of contaminant added.