Layer-by-layer stacked nano-CuZn5 for conductivity multi-enhancement and surface engineering of anode current collector in dendrite-free sodium metal batteries

In this study, we demonstrate that elastic strain applied to a current collector can influence the overall thermodynamic and kinetic picture of sodium metal electrodeposition and hence the performance of a sodium metal battery. To controllably study the role of strain in electrochemical performance, we utilize NiTi foil as a stable current collector, nucleation interface, and superelastic material. Our findings demonstrate that a locked-in elastic tensile strain near 8% results in 40 mV lower onset potential for sodium electrodeposition, 19% decrease in charge transfer resistance, and 20% lower cumulative sodium loss, among other effects. These performance improvements are correlated primarily to the control of the irreversible behavior in the first few minutes of electroplating. Given the prevalence of strain buildup in commercial battery cell configurations, our work highlights that strained current collector interfaces can result in significant long-term chemo-mechanical performance outcomes broadly relevant to sodium and other metal battery design considerations.

In response to escalating global energy demands and environmental concerns, the focus has shifted from lithium-metal batteries to sodium-metal batteries due to lithium's scarcity and rising costs. Sodium-metal batteries emerge as a promising alternative, providing a high theoretical specific capacity (~1166 mAh/g) and a low anode potential (-2.714 V vs. standard hydrogen electrode), all while being more abundant and cost-effective. However, their widespread adoption is impeded by the unstable and fragile solid electrolyte interphase (SEI) formed from spontaneous reactions between metallic sodium and liquid electrolytes. This instability leads to dendrite formation, which can cause short-circuiting and degrade battery performance. Addressing these challenges is crucial for unlocking the full potential of sodium-metal batteries as a viable and sustainable energy storage solution. This study introduces innovative mechano-electrochemical protective strategies to enhance the stability of sodium metal anodes, offering significant advancements toward long-life sodium-metal batteries and sodium solid-state batteries.Our study focused on the use of tin fluoride (SnF2) and silicon nitride (Si3N4) nano particles, both proven to form durable artificial SEI layers on the surface of sodium metal. These protective layers—enriched with NaF and Na3N compounds—significantly enhanced the cycling performance of the batteries. They effectively suppressed dendrite formation, improving the cycling stability of the sodium anodes by approximately 5.5 times (1100) hours compared to uncoated sodium anodes.Building on these foundational insights, we developed a novel hybrid protective strategy by integrating polyethylene oxide (PEO) with SnF2 as an additive. This combination was carefully selected to provide chemical stability, morphological adaptability, and mechanical flexibility for addressing the challenges encountered during sodiation and desodiation.The synergy between PEO and SnF2 maximized the strengths of both materials, yielding a composite artificial SEI with outstanding cycling performance. Under a 0.25 mA/cm2 current density in a carbonate-based electrolyte (1M NaPF6 in 1:1 EC/DMC), the hybrid system achieved 10 times better performance compared to bare sodium, maintaining stability for up to approximately 2000 hours. Even under a more challenging 0.5 mA/cm2 current density, it continued cycling for 800 hours, significantly outperforming untreated sodium metal. Furthermore, at 0.5 mA/cm2 in ether-based electrolyte (1M NaPF6 in tetraglyme), the composite SEI extended cycling to an impressive 3000 hours. This hybrid system efficiently minimized electrolyte decomposition, prevented dendrite formation, and stabilized the plating and stripping processes, underscoring its potential to advance sodium metal battery technology.To further leverage these advancements, an innovative polymer electrolyte directly on the sodium surface was developed by hybrid solution containing NaPF6 onto the sodium anode. This unique approach enables the formation of a solid polymer electrolyte layer directly on the sodium surface, enhancing ion conduction and acting as both an polymer solid electrolyte and a protective SEI. This configuration offers a new pathway for polymer electrolytes in sodium batteries. We also extended this concept by developing a standalone polymer electrolyte system composed of PEO, SnF2, and NaPF6. This polymer electrolyte demonstrated promising performance in half-cell configurations, showing stable cycling behavior and improved ion transport.The integration of these hybrid polymer-based solutions underscores a significant leap toward the development of reliable and high-performance sodium-metal batteries. These strategies not only stabilize the sodium anode but also enhance the longevity and safety of the batteries, presenting an important step in overcoming the challenges of dendrite growth, SEI instability, and electrolyte degradation.

Evaluating the suitability of tungsten, titanium and stainless steel wires as current collectors in microbial fuel cells.

P25] Assessment of temperature and pressure dependence of molar volume and phase diagrams of Al, Cu, Si, and Zn

Direct electron transfer (DET) processes in a flow anode system–Energy-efficient electrochemical oxidation of phenol

Performance improvement and redox cycling of a micro-tubular solid oxide fuel cell with a porous zirconia support

The current collector (CC) components (bipolar plate and porous transport layer) of a polymer electrolyte membrane water electrolyser (PEMWE) comprise one of the highest proportion of the cost of the stack [1]. It is widely accepted that the PEMWE CC material needs to withstand the relatively high potentials encountered at the anode electrode, with ex situ qualification testing typically carried out at an applied potential of at least 2 V vs the standard hydrogen electrode (SHE). As a result, platinum-coated titanium is the common material of choice. However, we offer a counter hypothesis that it is unlikely that the corrosion potential of the anode CC is equal to that of the anode electrode due to the very low ionic conductivity of the pure water phase separating the two components.In this work, an innovative in situ reference electrode consisting of a Nafion®/H2SO4 salt bridge connected to a reversible hydrogen electrode is used to measure the corrosion potential of the anode CC during PEMWE cell operation. Using this technique, we demonstrate for the first time that the corrosion potential of the anode current collector is effectively decoupled from that of the anode electrode [2]. Furthermore, we demonstrate that carbon paper can be applied as anode CC material without any noticeable corrosion taking place.The implications of this work are that significantly cheaper materials such as carbon or carbon-coated stainless steel can be used for CC components, which could reduce the cost of PEMWE technology substantially. The key advance is the use of a thin porous spacer layer between the anode and the CC. Factors that may influence the implementation of this new concept are discussed, including the influence of spacer layer tortuosity and water conductivity on the corrosion potential of the CC.

In this work, the effect of the current-collector structure on the performance of a passive direct methanol fuel cell (DMFC) was investigated. Parallel current-collector (PACC) and other two kinds of perforated current collectors (PECC) were designed, fabricated and tested. The studies were conducted in a passive DMFC with active membrane area of 9 cm2, working at ambient temperature and pressure. Two kinds of methanol solution of 2 M and 4 M were used. Results showed that the PACC as anode current-collector has a positive effect on cell voltage and power. For the cathode current-collector structure, the methanol concentration of 2 M for PECC-2 (higher open ratio 50.27 %) increased performance of DMFC. But the methanol concentration of 4 M led to an enhancement of fuel cell performance that used PACC or PECC-2 as cathode current-collector.

We have proposed a novel micro-tubular solid oxide fuel cell (SOFC) design with an inert support and an integrated current collector for the inner electrode to improve current collection efficiency as well as reduction–oxidation stability of the cell. In this work, a micro-tubular SOFC based on the proposed design was fabricated using scandia-stabilized zirconia (ScSZ) as electrolyte owing to its high ionic conductivity over a wide range of temperatures. Yttria-stabilized zirconia (YSZ), Ni, Ni-ScSZ, strontium-doped lanthanum manganite (LSM)–ScSZ, and LSM were used as the inert support, anode current collector, anode, cathode, and cathode current collector, respectively. The electrochemical performance of the fabricated cell was evaluated at temperatures between 600 and 850°C. Because of the lower ohmic resistance across its components, the cell exhibited good power generation performance at high and intermediate temperatures. Additionally, we confirmed stable operation of the micro-tubular SOFC for over 60 h at 750°C.

Improved electrochemical performance of the Silicon/Graphite-Tin composite anode material by modifying the surface morphology of the Cu current collector

Sodium metal batteries are arousing extensive interest owing to their high energy density, low cost and wide resource. However, the practical development of sodium metal batteries is inherently plagued by the severe volume expansion and the dendrite growth of sodium metal anode during long cycles under high current density. Herein, a simple electrospinning method is applied to construct the uniformly nitrogen-doped porous carbon fiber skeleton and used as three-dimensional (3D) current collector for sodium metal anode, which has high specific surface area (1,098 m2/g) and strong binding to sodium metal. As a result, nitrogen-doped carbon fiber current collector shows a low sodium deposition overpotential and a highly stable cyclability for 3,500 h with a high coulombic effciency of 99.9% at 2 mA/cm2 and 2 mAh/cm2. Moreover, the full cells using carbon coated sodium vanadium phosphate as cathode and sodium pre-plated nitrogen-doped carbon fiber skeleton as hybrid anode can stably cycle for 300 times. These results illustrate an effective strategy to construct a 3D uniformly nitrogen-doped carbon skeleton based sodium metal hybrid anode without the formation of dendrites, which provide a prospect for further development and research of high performance sodium metal batteries.

Anode‐free sodium metal batteries (AFSMBs) are considered one of the most promising large‐scale energy storage systems due to their extremely high energy density. Nonetheless, their practical application is hindered by the uncontrolled growth of sodium dendrites. Constructing a mechanically robust solid electrolyte interphase (SEI) is an effective strategy to suppress dendrite formation. Herein, we report a catalysis chemistry approach to construct an ultra‐thin (∼ 5 nm), NaF‐rich and high‐strength (203 MPa) SEI layer by introducing Ru catalytic sites on the current collector, which promotes rapid Na⁺ diffusion and effectively inhibits dendrite growth. Benefiting from this design, the Ru modified‐Cu//Na asymmetric cells exhibit exceptional cycling stability over 2000 h (1000 cycles at 2 mA cm−2, 2 mAh cm−2). Furthermore, the AFSMBs with Ru modified‐Cu current collector also deliver excellent cycling performance and maintains nearly 98.1% capacity retention after 100 cycles at 0.5 C. The results demonstrate great potential of catalysis chemistry in developing advanced sodium metal anodes and provide a new perspective to engineering efficient SEI toward battery applications.

Flexible electrochemical energy sources using non-traditional cell materials and topologies have attracted growing attention because they offer unique design opportunities that are still being explored. They also offer potential advantages such as conformability, high power density, high specific power, and low cost through the adoption of electronics manufacturing techniques. This study examines the feasibility of using flexible printed circuits boards (PCBs) as the anode and cathode current collectors (CCs) of single cell Proton Exchange Membrane Fuel Cell (PEMFCs). In this work, we determine the best anode and cathode interfaces at which to embed flexible CCs to obtain the highest power, as illustrated in Figure 1. The flexible anode and cathode CCs are embedded A) inside the PEM|Catalyst Layer (CL) interface, B) between the CL|Micro Porous Layer (MPL) interface and C) between the Gas Diffusion Layer (GDL)| Flow field (FF) interface. The performance of the single cell PEMFC with the embedded flexible anode and cathode CCs at the different interfaces described in Figure 1 is investigated by using I-V polarization curves, electrochemical impedance spectroscopy (EIS), and thermal imaging. The performance of the cells tested with the embedded flexible CCs is compared to the performance of a standard cell. This study also investigates the effect of varying the anode and cathode CC geometry (square shape vs. circular) and opening ratio (20%, 30%, 40%, 50% and 60%) on the cell performance. Figure 1

8th International Conference on the Reduction of Drug Related Harm

Out of all the anode materials available for sodium ion batteries, sodium metal itself offersthe highest theoretical capacity. However, the direct use of sodium metal as anode is hindered by the challenges involved in processing the material, dendrite formation and high volume expansion. “Anode free” batteries are one of the most promising strategies to address these issues. In anode free sodium batteries, the sodium ions from the cathode are directly deposited on the anode current collector thorough the electrolyte and hence eliminate the use of sodium metal during the cell fabrication. Solid state electrolytes (SSE), on the other hand, are proposed to deal with the dendrite formation issues. Therefore, anode free sodium battery with a solid electrolyte is a fascinating electrochemical system which not only aims to solve majority of the issues with Na-metal batteries but also provides high volumetric energy density, safety and ease of fabrication.For a successful anode free battery, the behavior of sodium plating and stripping processes in different electrolytes/current collectors must be comprehended. Additionally, interfacial impedance is an area of major concern for solid electrolytes as well. Keeping this in mind, this work focusses on the study of the interfaces between solid electrolytes and anode current collectors. Interfacial properties of inorganic sodium super ionic conductor (NASICON) in combination with a polymer electrolyte (PVDF-HFP/NaPF6/TEGDME) are studied with respect to copper/3D carbon cloth current collector using electrochemical impedance spectroscopy. Sodium stripping and plating processes are studied with respect to both sodium electrodes and Na2S based cathodes and an anode free Na-S battery is demonstrated with the optimized combinations of SSEs and current collectors.