Anode Cathode Research Articles

Automated Electrophoretic Deposition Module Design and Ca-Coated A7075 Corrosion Study

This study investigates the installation and operation of an automated electrophoretic deposition (EPD) unit for applying Ca coatings on aluminum alloy parts, with a focus on optimizing electrode distance and deposition parameters. The dynamic adjustment of the anode–cathode distance during the process was crucial in influencing the uniformity and adhesion of the Ca coating. The electrolyte solution consisted of 50% acetone, 50% distilled water and 5[Formula: see text]g/500[Formula: see text]ml of pure Ca. The average thickness of the Ca coating was approximately 180 microns. Immersion corrosion tests revealed that after a 48[Formula: see text]h period, the coated sample lost 0.5[Formula: see text]g of weight, while the uncoated sample lost 1.1[Formula: see text]g. These findings demonstrate that the thickness and uniformity of the Ca coating significantly influence its protective properties. In conclusion, this study provides valuable insights into the optimization of EPD parameters and the role of Ca coatings in enhancing corrosion resistance in industrial applications.

Restricted growth of polyaniline nanofiber arrays between holey graphene sheets on carbon cloth towards improved charge storage capacity

The rapid−growing demand for flexible and wearable electronics has driven increased interest in developing porous electrodes with outstanding charge storage capacity especially areal capacity for polymeric and hybrid supercapacitors. Herein, unique porous polyaniline/holey graphene/carbon cloth (PANI/HG/CC) composite electrodes were constructed by combining rapid frozen interfacial polymerization and layer−by−layer spraying to restrict the growth of PANI nanofiber arrays between carbon−based materials. Benefiting from rapid charge transport, more electroactive sites and improved electrolyte penetration provided by hierarchical porous structure and highly oriented PANI nanofibers in the composite (P − G) by growing directly PANI array on the CC and applying graphene sheets as interlayer and cover layer, an areal specific capacitance of 3.22 F cm−2 at 5 mA cm−2 was achieved. A maximum areal energy density of up to 104.86 μWh cm−2, and excellent capacity retention of 89.5 % at 20 mA cm−2 after 5000 cycles also were achieved for flexible symmetric all−solid−state supercapacitor. Furthermore, the zinc−ion hybrid supercapacitor (P − G||Zn) assembled with P − G cathode and Zn anode could display a capacity of 217.7 mAh g−1 at 0.2 A g−1, and the maximum energy density of 130.6 Wh kg−1 at the power density of 120 W kg−1.

Experimental study on dissipative characteristics of cathode plasma of coaxial magnetically insulated transmission lines based on microwave interferometry

Flash x-ray radiography is an important diagnostic in hydrodynamic experiments to provide fluoroscopic imaging of fast-moving dense targets. In order to obtain multiple images of an object at different times in an experiment, a flash x-ray accelerator is required to output multiple pulses. For the induction voltage adder (IVA) multi-pulse accelerator, it is important to study the effect of the cathode plasma generated by the front pulse in magnetically insulated transmission lines (MITLs) on the transmission of the subsequent pulses. In this paper, a coaxial MITL experimental platform based on the “QiangGuang-I” accelerator is established to study the dissipation characteristics of the cathode plasma, and its working condition is similar to that of MITLs in typical IVA accelerators. In the experiment, a stable magnetic insulation is formed in the coaxial MITL, and the current loss along the line can be ignored. The microwave interferometer is used to measure the evolution of cathode plasma density over time for hundreds of microseconds after the pulse disappears. The measurement results of microwave interference show that the line-averaged density of the plasma in the anode–cathode gap is above 1 × 1018 m−3, and the time for the plasma density to decrease to 1 × 1016 m−3 is about 600 μs. The expansion velocity of the plasma after a pulse is much lower than that during the pulse. In addition, the dissipation characteristics of the cathode plasma with different electrical parameters of the pulses are compared and analyzed.

Theoretical study on electrochemical and thermal behavior of GNP incorporated anode materials for lithium-ion batteries

In this paper, a theoretical investigation of the electrical and thermal performance of lithium-ion batteries employing an unexplored graphene nanoplatelets (GNP) incorporated lithium titanate (LTO-GNP) anode and lithium manganese oxide cathode is demonstrated by using the COMSOL Multiphysics modeling and simulation. The GNP proportions in the LTO active material matrix are varied from 0 to 3 wt%, to assess the improvements in cell potential, state of charge (SOC), variation in internal temperature, discharging capacity, and battery power density across four selected electrodes. The simulation results have indicated the positive effects of increasing the anode’s GNP concentration on the battery performance, alongside temperature-dependent open-circuit voltage (OCV) and SOC outputs of the battery. The analysis of the effects of thermal conductivity on heat accumulation and dissipation within the battery has indicated that the anode with 3 wt% of GNP consistently performed superior to the other electrodes by providing uniform temperature distribution and enhanced electrical performance by promoting better discharge capacity and power density. The LTO anode with 3 wt% GNP has shown 0.2V more cell potential and also has 12.5% improved thermal conductivity when compared to LTO anode without GNP, contributing to better heat distribution inside the battery. The simulation also emphasized the importance of optimal GNP loading in the Li-ion battery anode to attain more uniform temperature distribution with improved battery health and efficiency.

Strengthened High-Concentration Quasi-Solid Electrolytes for Lithium Metal with Ultralong Stable Cyclability.

The lithium metal batteries coupled with nickel-rich LiNixCoyMn1-x-yO2 (x > 0.7) cathodes hold promise for surpassing the current energy density limit of lithium-ion batteries. However, conventional electrolytes containing free active solvents are highly susceptible to decomposition, particularly at the interfaces of lithium anode and high-voltage cathode. Herein, we have developed a composite quasi-solid electrolyte (CQSE) utilizing sulfated Al2O3 (S-Al2O3)-bridged cellulose triacetate (CTA) to stabilize the interfaces between the electrolyte and electrodes. S-Al2O3 competitively dissociates Li+ through coordination interactions with anions, facilitating the formation of a distinctive solvation structure characterized by prevalent ion pairs and aggregates. In addition, coordination of S-Al2O3 with CTA forms S-Al2O3-bridged CTA molecular chain networks, enhancing the mechanical strength of the CQSE and immobilizing free liquid molecules. Consequently, the CQSE demonstrates an enhanced tensile strength of up to 7.4 MPa and a high ionic conductivity of 1.8 × 10-3 S cm-1 at room temperature. Furthermore, the CQSE not only suppresses electrode-electrolyte side reactions but also enables the formation of an inorganic-rich solid/cathode electrolyte interphase. As a result, the Li|CQSE|LiNi0.83Co0.11Mn0.06O2 (NCM83) batteries retain 84% capacity after 1000 cycles at 1 C, with the pouch cells demonstrating 80% capacity retention after 250 cycles at 0.5 C.

Incorporation of Organic Benzoquinone Framework Into rGO via Strong π-π Interaction for High-Performance Aqueous Ammonium-Ion Battery.

Aqueous ammonium-ion batteries (AAIBs) are promising candidates for next-generation energy storage devices. However, organic materials as suitable anodes face severe challenges due to their structural instability and poor conductivity, which hinder the development of AAIBs. Herein, an innovative approach is introduced by incorporating an organic benzoquinone framework, 5,7,11,14-tetraaza-6,13-pentacenequinone (TAPQ), with reduced graphene oxide (rGO) using a solvent exchange method. Benefiting from π-π interaction and electron delocalization, TAPQ/rGO features enhanced cycling stability and ion/electron transportation. Consequently, the composite electrode delivers a reversible capacity of 181.7 mAh g-1 at 0.5 A g-1 and achieves an ultrahigh capacity retention of 94.5% over 10000 cycles at 5 A g-1, surpassing most reported anodes in AAIBs. Combining density functional theory (DFT) calculation and ex situ electrochemical characterizations, the unique storage mechanism of chelation coordination between NH4 + and N, O is revealed. Furthermore, a high-performance NH4 +-based full cell, assembled with TAPQ/rGO anode and copper hexacyanoferrate (Cu-HCF) cathode, demonstrates long-term cycling stability with 93.95% capacity retention after 500 cycles. This work pioneers the concept of π-π interactions to significantly improve NH4 + storage performance, presenting a novel strategy for the advancement of AAIBs research.

Classification and Analysis of Halide Mixtures in Li10P3S12M (M = Cl, Br, I) Solid Electrolytes for Superionic Conductors.

The lithium thiophosphate group of solid electrolytes (SEs) is considered one of the best lithium-ion conductors that could be compatible with liquid electrolytes. However, the interface stability of lithium thiophosphate SEs against the lithium anode and oxide cathode could be a challenge due to severe degradation over charge-discharge cycles. In this study, we aim to analyze and introduce the addition of halides into lithium thiophosphate SEs with a molar ratio of 3Li3PS4 to 1LiM (M = Cl, Br, I) in order not only to improve ion conductivity but also to increase the interface stability of the SEs. Li10P3S12Br (LPSBr) and Li10P3S12I (LPSI) results in high ionic conductivity at 1.7 and 2.9 mS cm-1, respectively, at room temperature. Although LPSBr has lower ion conductivity, it shows better electrochemical stability compared to LPSI. By combining the advantages of both LiI and LiBr to form Li10P3S12Br1-xIx, we have observed improvements not only in high ionic conductivity but also in the interface stability of SEs, which is important for extending the lifetime cycle of all-solid-state lithium batteries (ASSLBs).

Tailoring Na2FePO4F nanoparticles as the high-rate capability and Long-life cathode towards fast chargeable sodium-ion full batteries

Na2FePO4F (NFPF) with two-dimensional channels for transferring Na ions is considered as the promising cathode material for high-performance sodium-ion batteries (SIBs), while the electrochemical performance in full-cell devices remains unsatisfactory. Here, we developed a method combining high-boiling organic solvents assisted colloidal synthesis (HOS-CS) and subsequent calcination for preparing 20–30 nm of NFPF nanoparticles (NPs) wrapped by conductive carbon as the efficient cathode. HOS-CS demonstrated merits in terms of high utilization of precursors, high synthetic efficiency, and uniform distribution of both sizes and composition of NPs. Impressively, the as-obtained NFPF/C/MWCNTs delivered a reversible capacity up to 118.4 mAh/g at 0.1C. As a bonus, the full-cell configuration fabricated via NFPF/C/MWCNTs cathode and hard carbon (HC) anode demonstrated extraordinary rate capability and cyclic stability. Even at an ultrahigh rate of 10C, 54.7 mAh/g of initial reversible capacity and nearly 80.7 % of capacity retention after 200 cycles were achieved, highlighting the great potentials of NFPF/C/MWCNTs||HC full cell for practical applications in the fields of fast chargeable SIBs. This work offers a novel synthetic method for the preparation of efficient NFPF-based cathode.

A MXene Modulator Enabled High‐Loading Iodine Composite Cathode for Stable and High‐Energy‐Density Zn‐I2 Battery

AbstractAchieving both high iodine loading cathode and high Zn anode depth of discharge (DOD) is pivotal to unlocking the full potential of energy‐dense Zn‐I2 batteries. However, this combination exacerbates the detrimental shuttle effect of polyiodide intermediates, significantly impairing the battery's reversibility and stability. Herein, this study reports an advanced high‐loading iodine cathode (denoted as MX‐AB@I) enabled by a multifunctional Ti3C2Tx MXene modulator, which presents high stability and energy density in Zn‐I2 batteries. Through comprehensive experimental and theoretical analyses, the intrinsic regulating mechanisms are elucidated by which the MXene modulator effectively suppresses polyiodide shuttling, enhances iodine conversion kinetics, and dramatically improves Zn anode reversibility. With the aid of the MXene modulator, the MX‐AB@I composite cathode achieves a high iodine mass loading of 23 mg cm−2 and realizes a practically high areal capacity of 4.0 mAh cm−2. When paired with a thin Zn anode (10 µm), this configuration realizes a high Zn DOD of 78.7% and a high energy density of 171.3 Wh kg−1, surpassing the majority of Zn‐I2 battery systems reported in the literature. This study presents an effective approach to designing high‐loading iodine cathodes for Zn‐I2 batteries by leveraging MXene modulators to regulate critical electrochemical reaction processes.

Improving Oxygen-Redox-Active Layered Oxide Cathodes for Sodium-Ion Batteries Through Crystal Facet Modulation and Fluorinated Interfacial Engineering.

Layered oxides with active oxygen redox are attractive cathode materials for sodium-ion batteries (SIBs) due to high capacity but suffer from rapid capacity/voltage deterioration and sluggish reaction kinetics stemming from lattice oxygen release, interfacial side reactions, and structural reconstruction. Herein, a synergistic strategy of crystal-facet modulation and fluorinated interfacial engineering is proposed to achieve high capacity, superior rate capability, and long cycle stability in Na0.67Li0.24Mn0.76O2. The synthesized single-crystal Na0.67Li0.24Mn0.76O2 (NLMO{010}) featuring increased {010} active facet exposure exhibits faster anionic redox kinetics and delivers a high capacity (272.4 mAh g-1 at 10mA g-1) with superior energy density (713.9Wh kg-1) and rate performance (116.4 mAh g-1 at 1 A g-1). Moreover, by incorporating N-Fluorobenzenesulfonimide (NFBS) as electrolyte additive, the NLMO{010} cathode retains 84.6% capacity after 400 cycles at 500mA g-1 with alleviated voltage fade (0.27mV per cycle). Combined in situ analysis and theoretical calculations unveil dual functionality of NFBS, which results in thin yet durable fluorinated interfaces on the NLMO{010} cathode and hard carbon anode and scavenges highly reactive oxygen species. The results indicate the importance of fast-ion-transfer facet engineering and fluorinated electrolyte formulation to enhance oxygen redox-active cathode materials for high-energy-density SIBs.

Molecular Crowding Solid Polymer Electrolytes for Lithium Metal Battery by In Situ Polymerization

AbstractSolid‐state polymer electrolytes (SPEs) require high ionic conductivity and dense contact with the electrodes for high‐performance lithium‐metal solid‐state batteries. However, massive challenges such as poor ionic migration ability, low antioxidant ability, and lithium dendrite formation still remain unresolved. These issues severely restrict its practical applications. Herein, a new type of solid‐state polymer electrolyte with a molecular crowding feature is rationally designed by in situ polymerization of a precursor containing poly (ethylene glycol) diacrylate (PEGDA) and 1,2‐dimethoxyethane (DME). Noticeably, the prepared SPE expands the electrochemical window to 4.7 V with a high lithium‐ion transfer number of 0.55 and a superior ionic conductivity of 3.6 mS cm−1 at room temperature. As a result, the lithium symmetrical batteries achieve stable cycles with more than 3000 h with no lithium dendrites at a current density of 0.5 mA cm−2. Importantly, this design provides dense contact of solid‐state polymer electrolytes with the porous cathode and lithium anode, allowing the assembled winding‐type solid‐state pouch cells with outstanding cycling stability of 81.7% retention for more than 340 cycles at room temperature. It shows excellent adaption to widely practical technology with large‐scale battery production, offering a new solution for the future development of solid‐state polymer lithium‐metal batteries.

Formicarium-Like Micron Porous Si Synergistically Adjusted by Surface Hard-Soft Nanoencapsulation as Long-Life Lithium-Ion Battery Anode.

Micron porous silicon (MPSi) is a promising lithium-ion battery (LIB) anode that can provide enough space to effectively alleviate the volume expansion and large number of transmission channels to rapidly transport the Li-ions. However, a long-term stable MPSi anode at high current density is still a great challenge. Herein, a double-regulated formicarium like-MPSi composite using the surface hard-soft titanium dioxide-few layered MXene nanotemplate (FMPSi@TiO2@FMXene) was designed and synthesized via an in situ assembly strategy as long-life LIB anode. Such hard-soft TiO2-FMXene nanoencapsulation can collaboratively tune the internal/external stress, inhibit the volume expansion, reduce the interfacial reactions, and improve the electrical conductivity of MPSi, resulting in the great enhancement of structural stability and electrochemical performance in cycling even at high current density. Especially, this FMPSi@TiO2@FMXene anode exhibits a high reversible capacity of 1254.9 and 970.4 mAh/g after 500 cycles at 0.5 and 1 A/g, respectively. Moreover, a full cell is assembled with the FMPSi@TiO2@FMXene anode and commercial LiFePO4 (LFP) cathode, exhibiting a high capacity retention rate of 91.6% in 100 cycles. This work provides an effective surface nanoengineering tactic to obtain the structurally stable MPSi anodes by hard-soft nanotemplate for large-scale and long-term LIB application.

Multifunctional Ultrathin Ti3C2Tx MXene@CuCo2O4 /PE Separator for Ultra-High-Energy-Density and Large-Capacity Lithium-Sulfur Pouch Cells.

The shuttling of lithium polysulfides (LiPSs), sluggish reaction kinetics, and uncontrolled lithium deposition/stripping remain the main challenges in lithium-sulfur batteries (LSBs), which are aggravated under practical working conditions, i.e., high sulfur loading and lean electrolyte in large-capacity pouch cells. This study introduces a Ti3C2Tx MXene@CuCo2O4 (MCC) composite on a polyethylene (PE) separator to construct an ultrathin MXene@CuCo2O4/PE (MCCP) film. The MCCP functional separator can deliver superior LiPSs adsorption/catalysis capabilities via the MCC composite and regulate the Li+ deposition through a conductive Ti3C2Tx MXene framework, enhancing redox kinetics and cycling lifetime. When paired with sulfur/carbon (S/C) cathode and lithium metal anode, the resultant 10 Ah-level pouch cell with the ultrathin MCCP separator achieves an energy density of 417Wh kg-1 based on the whole cell and a stable running of 100 cycles under practical operation conditions (cathode loading = 10.0 mg cm-2, negative/positive areal capacity ratio (N/P ratio) = 2, and electrolyte/sulfur weight ratio (E/S ratio) = 2.6 µL mg-1). Furthermore, through a systematic evaluation of the as-prepared Li-S pouch cell, the study unveils the operational and failure mechanisms of LSBs under practical conditions. The achievement of ultrahigh energy density in such a large-capacity lithium-sulfur pouch cell will accelerate the commercialization of LSBs.

Structural Regulation of P2‐Type Layered Oxide with Anion/Cation Codoping Strategy for Sodium‐Ion Batteries

AbstractP2‐type layered transition metal oxides are potential cathodes for sodium‐ion batteries (SIBs), but they commonly suffer from severe capacity degradation owing to multiple phase transitions and Na+/vacancy ordering during the extraction/insertion process. An anionic/cationic co‐doping strategy at high sodium contents is proposed to effectively achieve high‐rate and long‐term stability of P2‐Na0.67Ni0.33Mn0.67O2. The resulting Na0.75Mg0.1Ni0.23Mn0.67O1.95F0.05 (NMNMOF) cathode delivers a reversible capacity of 116 mAh g−1 at 75 mA g−1 and maintains an initial capacity of 73% at 1500 mA g−1 after 1000 cycles. The Mg/F anionic/cationic co‐doping strategy impacts the local environment of the surrounding transition metal and oxygen, regulates the electron distribution, and modifies the initial diffusion state of Na sites, enhancing the diffusion ability of Na+. Moreover, the phase transition of P2‐O2 is well suppressed and the decrease in Mn3+ content greatly alleviates the Jahn–Teller effect to enhance structural stability. The full‐cell devices with NMNMOF cathode and hard carbon anode demonstrate a high capacity of 80 mAh g−1 at 10 C and an excellent cycle life of over 500 cycles for applications. The anionic/cationic co‐doping strategy will inspire the rational design of P2‐type layered oxides and provide a new perspective for advanced SIBs.

Electrolyte Design Enables Stable and Energy-Dense Potassium-Ion Batteries.

Free from strategically important elements such as lithium, nickel, cobalt, and copper, potassium-ion batteries (PIBs) are heralded as promising low-cost and sustainable electrochemical energy storage systems that complement the existing lithium-ion batteries (LIBs). However, the reported electrochemical performance of PIBs is still suboptimal, especially under practically relevant battery manufacturing conditions. The primary challenge stems from the lack of electrolytes capable of concurrently supporting both the low-voltage anode and high-voltage cathode with satisfactory Coulombic efficiency (CE) and cycling stability. Herein, we report a promising electrolyte that facilitates the commercially mature graphite anode (>3 mAh cm-2) to achieve an initial CE of 91.14 % (with an average cycling CE around 99.94 %), fast redox kinetics, and negligible capacity fading for hundreds of cycles. Meanwhile, the electrolyte also demonstrates good compatibility with the 4.4 V (vs. K+/K) high-voltage K2Mn[Fe(CN)6] (KMF) cathode. Consequently, the KMF||graphite full-cell without precycling treatment of both electrodes can provide an average discharge voltage of 3.61 V with a specific energy of 316.5 Wh kg-1-(KMF+graphite), comparable to the LiFePO4||graphite LIBs, and maintain 71.01 % capacity retention after 2000 cycles.

Research Progress on Solid-state Electrolyte Interface Problems in Lithium-ion Batteries

Nowadays, compared with traditional liquid batteries, solid-state batteries have the superiorities of higher energy density, power density and safety due to their solid electrolytes. However, a series of interfacial problems at solid-solid interface have always hindered the further development of solid-state batteries. Based on these problems, this paper firstly introduces the types of solid-state batteries and interface, secondly describes the mechanical failure principles of cathode interface and anode interface, and finally elaborates the corresponding modification strategies for cathode interface and anode interface. By adopting various improved measures for these interfacial problems, the progress of wider commercialization of solid-state batteries can be facilitated.

2D MXene nanosheet dispersed Mn, Ru NPs loaded Ti composite electrodes for electrocatalytic synergistic degradation of antibiotics in high-salt mariculture wastewater

In this study, a composite electrode based on etched TiO2 nanotube arrays and two-dimensional (2D) MXene nanosheets was successfully designed for efficient degradation of antibiotics in mariculture wastewater. The composite electrode effectively dispersed Mn and Ru nanoparticles (NPs) by introducing 2D MXene nanosheets as an intermediate layer, which significantly enhanced the catalytic performance. The bifunctional properties of Mn and Ru NPs in catalysis and the contribution of d-orbital electrons to the formation of metal‑hydrogen bonds were revealed in depth by analyzing the electron transfer mechanism at the electrodes. The experimental results demonstrated a synergistic catalytic effect between Mn and Ru bimetals and MXene, resulting in an effective increase in the degradation rate. Under the optimal conditions, the degradation rate of Tetracycline (TC) by Mn/Ru/MXene/Ti composite electrode could reach 90.69 % in 60 min. In addition, it still shows excellent stability after 45 days of air exposure, 10 cycling experiments, and 10,000 s of timed current testing. Mechanistic studies have demonstrated that anode hydroxyl radical (·OH), HClO, and cathode activated hydrogen atoms (H*) all play catalytic roles in the degradation process. The degradation pathways were analyzed using density-functional theory (DFT) calculations and liquid-liquid-mass spectrometry (LC-MS) techniques, with further experiments confirming that this degradation process effectively reduces the biotoxicity of intermediate products, improving the safety of wastewater discharge. Finally, we designed the reactor and calculated the energy consumption to verify the feasibility and economy of the system in practical applications. This research proposes a novel multi-metal co-catalysis and cathode and anode co-catalysis system for the efficient degradation of antibiotics in mariculture wastewater, with potential applications in the electrocatalytic degradation of antibiotics.

Electro-assisted carbon nanotube dual catalytic membrane system for high-efficiency and energy-efficient water treatment

Improving performance of peroxymonosulfate (PMS) catalytic membrane via electrochemical assistance renders an effective way for water decontamination. However, the current cathodic or anodic membrane based electro-assisted PMS catalytic single-membrane systems (EPSM) usually suffer from their inherent deficiencies. Herein, a novel electro-assisted PMS catalytic dual-membrane system (EPDM) was constructed by employing two electro-conductive carbon nanotube membranes as the anodic and cathodic membranes, in order to couple the advantages of anodic and cathodic catalytic membranes for enhanced water treatment. Moreover, the filtration sequence (anode–cathode (A-C) or cathode–anode (C-A)) was varied to explore its effect on EPDM performance. Results showed the EPDM operated in C-A mode achieved ultrafast (0.95 s−1) and energy-efficient (0.008 kWh m−3) removal towards sulfamethoxazole (SMX), and its SMX mineralization rate was 1.7 times higher than that of EPDM operated in A-C mode and 5.1 or 2.4 times higher than that of cathodic or anodic membrane based EPSM. Meanwhile, the EPDM also displayed efficient fouling mitigation on both membrane surface and pores. Furthermore, EPDM can maintain high performance and good stability in long-term actual surface water treatment. The outstanding performance of EPDM operated in C-A mode was attributed to the collaboration of cathodic and anodic membranes: For one thing, cathodic and anodic membranes sequentially activated PMS to produce radicals (OH and SO4−) and non-radicals (1O2 and electron transfer) for enhanced pollutant oxidation; for another, both membranes in C-A mode effectively resisted coexisting interferents in real water.

Polarized polymer light-emitting electrochemical cells using polyfluorene and polycaprolactone blend film by floating-film transfer method

Abstract Sandwich-type structured polarized Polymer Light-emitting Electrochemical Cells (PLECs) of poly(9,9-dioctylfluorene) (PFO) successfully fabricated by combination of floating-film transfer method (FTM) and Post-blending ionic liquid (IL) procedure. An ion-solvating polymer, polycaprolactone (PCL), was blended in PFO for improving IL penetration. The PFO:PCL film showed clear optical dichroism due to the PFO backbone orientation. The IL, 1-Ethyl-3-methylimidazolium (trifluoromethylsulfonyl)imide (EMIm-TFSI), easily post-blended into the PFO:PCL blend FTM film without disordering PFO backbone orientation. The fabricated thickness varied PLECs with ITO anode and aluminum cathode were demonstrated distinct anisotropy, whole device area emission and low turn-on voltage compared to PLEDs.

Room-temperature ionic liquid electrolytes for carbon fiber anodes in structural batteries

Structural batteries require thermally stable electrolytes paired with carbon fibers (CFs), which offer advantages of lightweight, high mechanical strength, and good electrical conductivity. This work evaluated various room-temperature ionic-liquids (RTILs) as compatible electrolytes for CF anodes and LiFePO4 (LFP) cathodes on CFs. This LFP/CF full-cell design eliminates Cu and Al current-collectors, potentially enhancing gravimetric energy and reducing costs. Among various RTILs, LiTFSI in N-propyl-N-methylpyrrolidinium (PYR13) – bis(fluorosulfonyl)imide (FSI) offered promising LFP/CF full-cell performances, attributed to the formation of solid electrolyte interphase (SEI) layer on the CF anode with components such as Li2Sx, Li2S–SO3, LiF, LixFy and F–SO2, identified through X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) analyses further confirmed the electrochemical stability of the SEI layer on CF anodes. The LFP/CF cell delivered an initial capacity of 119 mAh/g and relatively high Coulombic efficiency when using the 1 M LiTFSI in PYR13-FSI. CF cycled in different electrolytes exhibit varying mechanical properties with up to 10.08 % loss in tensile strength, which may be related to CF surface degradation during cycling. The 1 M LiTFSI in PYR13-FSI is non-flammable, offering a significant thermal safety. This work successfully demonstrated the significant potential of 1 M LiTFSI in PYR13-FSI RTILs, which enables the use of CF as both an anode active material and cathode current collector for structural battery applications.