Improved Cell Performance Research Articles

Indium Nanoparticle‐Decorated Graphite Felt Electrodes for Efficient and Long‐Cycle Zinc‐Bromine Flow Batteries

AbstractZinc‐bromine flow batteries (ZBFBs) offer the potential for large‐scale, low‐cost energy storage; however, zinc dendrite formation on the electrodes presents challenges such as short‐circuiting and diminished performance. Herein, an indium nanoparticle‐decorated graphite felt composite electrode for ZBFBs is proposed to mitigate zinc dendrite formation, improve performance, and prolong operational longevity. Using a facile in situ electrodeposition method, indium nanoparticles are uniformly and densely distributed on the carbon fiber surface, demonstrating exceptional efficacy in regulating zinc deposition. Thus, a higher prevalence of Zn (002) crystal planes and a smoother and more compact surface morphology are obtained, compared with those of thermally treated graphite felt. Furthermore, integration of the composite electrode into the negative side of a ZBFB yielded substantial improvements in cell performance, achieving an energy efficiency of 66.83% ± 0.45% at 120 mA cm−2, significantly surpassing the performance of batteries utilizing thermally treated graphite felt (52.64% ± 1.50%). Notably, the cycle life of the battery is extended by more than five‐fold with the composite electrode, underscoring the remarkable zinc deposition‐regulating capabilities of the indium nanoparticles.

Role of La2CuO4 as Buffer Layer for a Significant Improvement of the Performance of TiO2/Cu2O Based All‐Oxide Solar Cell: A SCAPS‐1D Numerical Analysis

AbstractCurrently, low‐bandgap Mott‐insulating materials are the most promising buffer layers (BLs) for solar power conversion efficiency, unlike organic‐halide or lead‐containing perovskite materials. They can reduce interfacial recombination by field effect passivation of heterojunctions while maintaining cost‐effectiveness and high thermal and electrical stability. Moreover, it is expected to obtain a high quantum efficiency due to multiple carrier generation caused by impact ionization from a single incident photon. This study uses the SCAPS‐1D simulator to estimate and improve the efficiency of Cu2O‐based solar cells using Mott insulator La2CuO4 (LCO) as a BL in both ideal and non‐ideal conditions. The simulations examine how BL thickness, carrier concentration, and defect density affect device performance. Also, different metal contact work functions and working temperatures are examined to improve cell performance. Considering all optimisation parameters in ideal conditions, Au/Cu2O/TiO2/Nb: STO solar cell structure without a BL has a PCE of 11.27%, while Au/Cu2O/LCO/TiO2/Nb: STO has 28.11%. By incorporating non‐idealities, the simulated solar cell can simulate actual conditions. The impact of each non‐ideality is studied in detail. These findings suggest that Mott insulating buffer materials have great potential for creating high‐efficiency photovoltaic (PV) devices, presenting a new avenue for research.

Performance Characteristics of a Free-Breathing Polymer Electrolyte Fuel Cell with Various Channel Shapes

This study utilized a small free-breathing fuel cell, with an active area of 4 cm2 (2 cm x 2cm), and channel cathodes with various channel shapes, to experimentally investigate the effect of channel structure on cell performance, to numerically analyze the natural convection air flow in channels, and to compare with the results of performance characterisitics. The results indicated that, compared with a conventional cathode separator with four straight channels (with a width of 3 mm, a depth of 3 mm, and a rib width of 2 mm), cell performance was improved by eliminating some of the channel ribs and increasing the opening ratio, up to a point. A separator with 2 mm square ribs rotated by 45° further improved cell performance. However, when the opening ratio exceeded 72% with a straight center rib of 2 mm width, cell performance leveled off. The analysis results revealed that separators with modified channels promoted natural convection.

Numerical Analysis on Influence of Double-Sided 3D-Patterned Cathode Catalyst Layers on Polymer Electrolyte Fuel Cell Performance

Abstract An optimized cathode catalyst layer (CCL) design can improve fuel cell performance. In this study, we tried to optimize the structure by investigating the electrochemical properties of ion and mass transport through various CCL structures with ionomer layer (IL) added using simulation numerical analysis. In the simulation, an electrochemical calculation was performed on the structure with polymer electrolyte membrane (PEM) and IL of CCL using multi-block model. The simulation was conducted by changing the aspect ratio (AR) structure of width and height of IL to five conditions so that IL is evenly distributed in catalyst layer (CL). The result confirmed that CL 3D IL AR 4.9 structure with the highest aspect ratio showed good performance. In addition, cell performance improved as the uniform reaction area with protons conducting through IL increased and the resistance of protons decreased. Finally, cell performance was predicted based on changes in oxygen concentration (OC), relative humidity (RH), and ionomer/carbon (I/C) ratio. This numerical analysis can show the reaction according to environmental and structural changes and design an optimized structure to improve cell performance.

Overview of Recent Solar Photovoltaic Cooling System Approach

In recent years, research communities have shown significant interest in solar energy systems and their cooling. While using cells to generate power, cooling systems are often used for solar cells (SCs) to enhance their efficiency and lifespan. However, during this conversion process, they can generate heat. This heat can affect the performance of solar cells in both advantageous and detrimental ways. Cooling cells and coordinating their use are vital to energy efficiency and longevity, which can help save energy, reduce energy costs, and achieve global emission targets. The primary objective of this review is to provide a thorough and comparative analysis of recent developments in solar cell cooling. In addition, the research discussed here reviews and compares various cooling systems that can be used to improve cell performance, including active cooling and passive cooling. The outcomes reveal that phase-change materials (PCMs) help address critical economic goals, such as reducing the cost of PV degradation, while enhancing the lifespan of solar cells and improving their efficiency, reliability, and quality. Active PCMs offer precise control, while passive PCMs are simpler and more efficient in terms of energy use, but they offer less control over temperature. Moreover, an innovative review of advanced cooling methods is presented, highlighting their potential to improve the efficiency of solar cells.

Chemically programmed metabolism drives a superior cell fitness for cartilage regeneration.

The rapid advancement of cell therapies underscores the importance of understanding fundamental cellular attributes. Among these, cell fitness-how transplanted cells adapt to new microenvironments and maintain functional stability in vivo-is crucial. This study identifies a chemical compound, FPH2, that enhances the fitness of human chondrocytes and the repair of articular cartilage, which is typically nonregenerative. Through drug screening, FPH2 was shown to broadly improve cell performance, especially in maintaining chondrocyte phenotype and enhancing migration. Single-cell transcriptomics indicated that FPH2 induced a super-fit cell state. The mechanism primarily involves the inhibition of carnitine palmitoyl transferase I and the optimization of metabolic homeostasis. In animal models, FPH2-treated human chondrocytes substantially improved cartilage regeneration, demonstrating well-integrated tissue interfaces in rats. In addition, an acellular FPH2-loaded hydrogel proved effective in preventing the onset of osteoarthritis. This research provides a viable and safe method to enhance chondrocyte fitness, offering insights into the self-regulatory mechanisms of cell fitness.

Exploring the theoretical potential of tungsten oxide (WOx) as a universal electron transport layer (ETL) for various perovskite solar cells through interfacial energy band alignment modulation

Perovskite solar cells (PSCs) play a pivotal role in advancing renewable energy to achieve United Nation's Sustainable Development Goal 7 (SDG 7), which aims to ensure universal access to affordable, sustainable, reliable and modern energy services. Aiming to enhance the performance of PSCs by replacing the typically used electron transport layers (ETLs: TiO2, SnO2, ZnO etc.), we theoretically investigated the viability of tungsten oxide (WOX) as a promising ETL for PSCs. Moreover, the effect of altering the energy levels of WOX on cell performance has also been analyzed through simulation. Initially, 12 (twelve) PSC structures having the combination of different perovskite (PSK: CsPbBr3, CsPbI3, FAPbBr3, FAPbI3) absorber layers with different organic hole transport layers (HTLs: Spiro-OMeTAD, P3HT, PEDOT:PSS) and a fixed ETL of WOX were optimized numerically for comparing their performance. As CsPbBr3-based PSCs showed the best performance, further simulations were performed by varying some WOX/CsPbBr3 interface properties such as interface defect density, conduction band offset (CBO) between WOX and CsPbBr3, energy bandgap (Eg) of WOX etc. Finally, the best-performed PSCs were found for the Eg = 3.5 eV of WOX and the CBO of - 0.5 eV confirming the conduction band minimum (CBM) of WOX is lower than that of CsPbBr3 by 0.5 eV. A properly chosen WOX layer enhanced the efficiency of CsPbBr3-based PSCs up to 14.65 %, 14.52 % and 16.09 %, aproaching the Shockley-Queisser (S-Q) limit (16.37% for CsPbBr3-based solar cell) from the initial values of 11.39 %, 11.27 %, and 12.49 %, respectively. This study ensures WOX is a promising ETL for which a proper PSC structure having a suitable PSK and an HTL can improve cell performance. Moreover, the importance of modifying energy levels of ETL material in enhancing the performance of PSCs is explored. As a result, this study opens a path for the researchers to develop WOX having suitable CBM and Eg, so that it can be well-suited with a properly matched PSK material resulting in enhanced cell performance.

Cathode catalyst layer aging of proton exchange membrane fuel cell during emulated start-up/shut-down phases

Start-up and Shut-down phases for Proton Exchange Membrane Fuel Cell stacks are known to damage the Cathode Catalyst Layer inducing an irreversible loss of performance. An original Accelerated Stress Test has been designed to mimic the Start-up phase in real-life system conditions. The impact of cathode potential on the degradation mechanisms of the Pt/C components within the Cathode Catalyst Layer by local electrochemical and physicochemical analyses provided a deep understanding of the cathode evolution. An unexpected cell performance improvement is observed between 1.0 and 1.2 V cathode potential, especially at high current density. A beneficial modification of the properties occurs suggesting that fresh Cathode Catalyst Layer exhibits non-optimized carbon support properties. However, a significant structure subsidence appears when the cathode potential is above 1.4 V. In this condition, modification/compaction of cathode layer due to carbon corrosion alters mass transport and empathizes water flooding through the electrode.

Theoretical Investigation of the Effects of Aldehyde Substitution with Pyran Groups in D-π-A Dye on Performance of DSSCs.

This work investigated the substitution of the aldehyde with a pyran functional group in D-π-aldehyde dye to improve cell performance. This strategy was suggested by recent work that synthesized D-π-aldehyde dye, which achieved a maximum absorption wavelength that was only slightly off the threshold for an ideal sensitizer. Therefore, DFT and TD-DFT were used to investigate the effect of different pyran substituents to replace the aldehyde group. The pyran groups reduced the dye energy gap better than other known anchoring groups. The proposed dyes showed facile intermolecular charge transfer through the localization of HOMO and LUMO orbitals on the donor and acceptor parts, which promoted orbital overlap with the TiO2 surface. The studied dyes have HOMO and LOMO energy levels that could regenerate electrons from redox potential electrodes and inject electrons into the TiO2 conduction band. The lone pairs of oxygen atoms in pyran components act as nucleophile centers, facilitating adsorption on the TiO2 surface through their electrophile atoms. Pyrans increased the efficacy of dye sensitizers by extending their absorbance range and causing the maximum peak to redshift deeper into the visible region. The effects of the pyran groups on photovoltaic properties such as light harvesting efficiency (LHE), free energy change of electron injection, and dye regeneration were investigated and discussed. The adsorption behaviors of the proposed dyes on the TiO2 (1 1 0) surface were investigated by means of Monte Carlo simulations. The calculated adsorption energies indicates that pyran fragments, compared to the aldehyde in the main dye, had a greater ability to induce the adsorption onto the TiO2 substrate.

Research of electrode materials for the creation of multifunctional current sources with increased capacity as a components of the energy sector of an efficient urban environment

As part of creating a comfortable and safe environment, constructing energy-efficient residential and industrial buildings and structures that meet modern requirements and standards, the development of the production of environmentally friendly renewable and new individual energy sources is becoming especially relevant. In this regard, there is a need to increase the energy capacity of electrochemical cells. Research has been carried out on the metallized conductive materials creation based on rolled carbon non-woven material “Busofit” with the sequential application of metal coatings of titanium and silver using ion-plasma sputtering and electric pulse dispersion methods. It has been shown that surface layer metallization of the electrode material with titanium can improve the electrochemical cell characteristics. Additional silver film deposition leads to further cell performance improvement. It has been confirmed that the multilayer structure interfacial resistance between the carbon and the current collector has a significant effect on the conductivity of the electrochemical cell and the stability of its operation. The contact area increase of the electrode with the electrolyte leads to an increase in the rate processes occurring on the electrode surface and in the near-electrode space, which opens up prospects for increasing the energy intensity of the electrochemical system. A significant capacity increase of a water-based capacitor structure is achieved by the formation of a nanostructured dielectric layer of potassium titanate in the interelectrode space. It has been confirmed that the cell voltage cycling helps to stabilize the processes occurring in the surface layer of the electrode material at the interface and determining the range of mechanisms for transmitting electrical energy, which makes it possible to achieve higher energy intensity of the samples. Improvement of technological solutions in the field of ion-plasma technologies and the use of new perspective nanostructured materials creates the prerequisites for the creation of advanced automation and energy supply systems with a higher resource, which expands the possibilities of their use in various construction projects.

Quantitative performance analysis of anion-exchange membrane fuel cells with in-plane and through-plane water transport

Effective water management is crucial in anion-exchange membrane fuel cells (AEMFCs) due to water's dual role as a reactant during alkaline oxygen reduction and a product of alkaline hydroxide oxidation. Meanwhile, both hydroxide conduction and water transport in polymer electrolytes are highly dependent on the hydration level. Therefore, a three-dimensional multi-physics model is developed to investigate the critical role of ionic and water transport parameters of the electrolyte on AEMFC performance. Additionally, detailed water distribution analysis is used to reveal its fundamental mechanism. The results reveal that extremely inhomogeneous water distribution and cathode water starvation are the main causes of the poor cell performance. Moreover, increasing membrane water diffusivity, water conversion, and decreasing the electro-osmotic drag coefficient all contribute to better cell performance through improved water balance and cathode water supply. Among these, cell performance is most sensitive to membrane water diffusivity, with a 40 % increase in peak power density when it is increased from 10−10 m2 s−1 to 10−9 m2 s−1. Although high ionic conductivity improves cell performance by directly reducing ohmic impedance, it also results in a more inhomogeneous distribution of water in the whole cell, so that a four-fold increase in ionic conductivity only yields a 62 % increase in peak power density.

Degradation behavior of galvanostatic and galvanodynamic cells for hydrogen production from high temperature electrolysis of water

High temperature electrolysis of water using solid oxide electrochemical cells (SOEC) is a promising technology for hydrogen production with high energy efficiency and may promote decarbonization when coupled with renewable energy sources and excess heat from nuclear reactors. Apart from the technoeconomic considerations, commercial deployment of this technology critically depends on the long-term performance and durability of SOEC cells/stacks, especially under dynamic operations to withstand the intermittency of renewable energy. Herein, SOEC operation was conducted under galvanodynamic conditions and compared with galvanostatic cells to examine the effect on degradation behavior at an average current density of −0.75 A cm−2 at 750 °C. While dynamic operation shows no significant impact on the overall degradation rates compared to constant current operation, minor performance improvement was observed at potentials above 1.5 V when switched to galvanodynamic mode. The relatively lower overpotential during dynamic operation could not be explained by the negligible changes in the electrochemical impedance or cell temperature. Multiphysics modeling reveals that the oxygen partial pressure (PO2) in the electrolyte oscillates with the alternating current density under dynamic operations. The minor improvement in cell performance under dynamic mode might be associated with the relatively lower PO2 buildup as compared with that under galvanostatic operation. In addition, dynamic operation at high frequencies could effectively lower the extreme PO2 in the electrolyte, thus relieving stresses in the cells and alleviating cell degradation.

Flow flied inspired by sieve plate structure of plant leaf veins for proton exchange membrane fuel cells

Bionic flow fields have been applied in bipolar plates for proton exchange membrane fuel cells (PEMFCs) to significantly improve cell performance. This study, inspired by the vascular structure of plant leaf veins, proposes a bionic flow field that incorporates a sieve plate structure to enhance the distribution of reactants. To evaluate this design, a three-dimensional two-phase isothermal computational fluid dynamics (CFD) model was developed. The effect of hole parameters on the cell performance, such as opening ratio, hole number, and hole arrangement on the bionic sieve plate (BSP), was investigated and compared with a parallel flow field (PFF). The results showed that the peak power density of the bionic sieve plate flow field (BSPFF) was 0.991 W/cm2, 25.4% higher than that of the PFF, when the ratio of openings was 22.3%, the number of openings was 4, the sieve angle was 22.5°, and the number of sieves was 5. This BSPFF design provides insight into the development of bipolar plates to improve the performance of PEMFCs.

Effect of metal cation coaddition in phosphovanadomolybdate anion catholytes on the redox flow polymer electrolyte fuel cell performance

Redox flow polymer electrolyte fuel cells (RFFCs) employing heteropolyanions (HPAs) as cathode redox mediators enable continuous power generation through the electrochemical reduction of the HPAs at the carbon cathode and subsequent reoxidation of the reduced-form HPAs in the cathode tank. Currently, effective reoxidation methods are required to achieve both high performance and long-term stability. Heteropolyanions such as α–[PW12O40]3– and α–[SiVW11O40]5– have increased reoxidation rates in the presence of radical species. In this study, fuel cell performance is investigated by adding Fe3+ and Cu2+ to the aqueous solution of [PV3Mo9O40]6–, which is used as a catholyte in RFFCs to increase the concentration of radicals in the system. Current–voltage measurements show that the added metal cations in the catholyte increase the power density. A temporary improvement in cell performance is observed during a prolonged current passage test.

(Invited) Impact of Cell Performance and Degradation on the Levelized Cost of Hydrogen

For electrochemical production of hydrogen to be industrially relevant it must be economically viable. As such, it is important that a reasonable understanding of the entire breadth of cost components which make up the levelized cost of hydrogen (LCOH) should be obtained. While a precise and detailed understanding may be impossible due to costing uncertainty and a constantly changing basis, a general idea is necessary to determine the most impactful research topics. This work seeks to elucidate the impacts of cell performance on the LCOH in comparison to other aspects such as feedstock costs, capital equipment cost, and fixed business costs. Based on initial analysis it appears a doubling of current density at thermal neutral conditions, a substantial materials achievement, may reduce the LCOH by less than 5%. This infers that while improving cell performance will reduce the LCOH, it may not provide the highest return on engineering and scientific investigation.

Investigation and Characterization of Interfacial Transport Phenomena in the Catalyst Layer Using Rheo-Impedance Measurement

Electrodes or catalyst layers (CLs) are the heart of fuel cell and electrolyzer cell devices. They are mainly heterogeneous porous electrodes composed of catalyst particles, ion-conducting polymer material, and void spaces that make up the triple-phase boundary (TPB). It is important to tailor the CL’s microstructure such that there are abundant TPBs where reactions take place to maximize catalyst utilization and improve cell performance. However, this is a critical challenge due to lack of fundamental understanding of the interfacial transport within the CL. Understanding how catalyst ink parameters affect ink properties and how ink components interact, and ultimately, their relationship with CL microstructure formation and cell performance, are essential to designing electrodes. Electrode morphology is important and is controlled by the ionomer/catalyst interactions formed in precursor inks that evolve during mixing and electrode fabrication.In this study, we probe interactions in catalyst inks with different formulations (ionomer-to-carbon ratio and IPA/water) using a new experimental method to unravel the complexities of ionomer/catalyst particle interactions. The new experimental method is a combination of rheological and electrical impedance spectroscopy measurements (rheo-EIS) that takes advantage of the dynamic nature of catalyst ink and the fact that the rheological and electrical behaviors of the ink are coupled to the microstructure of the material. Using rheo-EIS tool, in combination with zeta (ζ) potential and dynamic light scattering (DLS) measurements, we were able to systematically study how the level of agglomeration of the inks and microstructures evolve with respect to different I/C ratios, solvent formulation, and external shear forces. Results from the three-phase rebuilt test designed to simulate the ink coating condition with single-frequency EIS measurement give information on how the ionomer/catalyst particle interactions form and recover during the coating process. In addition, the full frequency range EIS measurements provide complementary data of the ionic and electrical resistance of the ink before and after high shear applications. Furthermore, the observations of the effect of I/C and IPA/water ratios from this study provide insights on how to better engineer suitable catalyst inks and how to control specific CL microstructure without the need for time-consuming optimization and empirical studies.

An Analytical Model for an Anode-Supported Solid Oxide Fuel Cell

This study presents a one-dimensional, non-isothermal, steady-state model to analyze performance of an anode-supported solid oxide fuel cell (SOFC). The modeling domain encompasses components including a NiO-YSZ support and functional layer forming the anode, a YSZ electrolyte, a GDC interlayer, as well as LSCF+GDC and LSCF constituting the cathode. The model distinguishes different types of electrode polarization resistances using experimental impedance data at various temperatures under open circuit voltage (OCV), employing a detailed equivalent circuit model to determine the temperature and partial pressure dependencies of electrode exchange current densities. Moreover, this approach serves as an efficient method for estimating the conductivity of both the anode and cathode. As a result, activation energies and ohmic overpotentials are derived, considering microstructural and geometrical aspects, which allows for accurate quantification of the ohmic resistance associated with ionic conduction.The model incorporates coupled multi-physics elements, such as mass and charge transport, electrochemical reactions, and heat transfer. A notable feature of the model is its consideration of reaction zone layers near the electrolyte, where electrochemical reactions generate electrons, oxide ions, and water vapor. Enhancing prediction accuracy, the model applies multilayer discretization within the electrode and electrolyte to reflect actual material properties and localized conditions more accurately. The model predicts the performance of a single-cell SOFC using pure hydrogen at the anode and varying oxygen concentrations (100%, 50%, 20%, and 10%) at different operating temperatures (700°C, 660°C, 620°C, and 580°C) and design conditions. Simulated results are compared with experimental data, and the impact of various operating and design parameters on SOFC performance is examined. Findings indicate that kinetic and concentration overpotentials in an anode-supported SOFC are lower than ohmic overpotentials, even at higher current densities. Furthermore, ohmic overpotential is identified as the primary contributor to total cell potential loss, highlighting the need for its minimization to improve cell performance.

Enhancement of Mass Transport in Catalyst Layers of HT-PEMFC with Tetrafluorophenyl Phosphonic Acid Binder.

The design and development of new and efficient catalyst binder materials are important for improving cell performance in high-temperature proton-exchange membrane fuel cells (HT-PEMFCs). In this study, a series of tetrafluorophenyl phosphonic acid-based binder materials (PF-y-P, y = 1, 0.83, and 0.67) with rigid structures and controllable degrees of phosphonation were prepared and used in HT-PEMFCs using the ultra-strong acid-catalyzed Friedel-Crafts reaction and the combined Michaelis-Arbuzov reaction. The samples exhibited high stability, low water uptake, superior proton conductivity, and cell performance. In addition, the oxygen mass transport properties of the PF-1-P binder were investigated using high-temperature microelectrode electrochemical testing techniques. Compared with the phosphoric acid-doped polybenzimidazole (PBI) binder, the O2 solubility of PF-1-P binder material increased by 30% (5.36 × 10-6 mol cm-3) and the PF-1-P binder material exhibited better cell stability in HT-PEMFCs. After 10.5 h of discharge at a constant current of 0.12 A cm-2, the MEA voltage decreased by 7.1% and 20.8% in case of the PF-1-P and PBI binders, respectively.

Incorporation of electronically and ionically conductive additives in high-loading sulfur cathodes in lean-electrolyte lithium–sulfur cells

Low-cost, high-energy-density lithium–sulfur electrochemical batteries have emerged as a promising solution for next-generation energy-storage technologies. To facilitate the practical application of such batteries, it is necessary to address the remaining scientific and engineering challenges, especially those associated with the high-loading sulfur cathode in a lean-electrolyte cell. In this study, we investigate the electrochemical and overall performance of lithium–sulfur cells with a high-loading sulfur cathode. Notably, this cathode is fabricated using a novel hot-pressing method and incorporates electronically and ionically conductive additives, specifically lithium lanthanum titanate (LLTO) and carbon black, respectively. Material analysis reveals the uniform distribution of additives in the cathodes, with the ionically conductive LLTO effectively adsorbing and converting polysulfides and carbon black enhancing the cathode conductivity. Electrochemical analysis of the lean-electrolyte cells shows that the incorporation of LLTO improves cell performance, with enhanced discharge capacity of 715–836 mAh g−1 at C/5–C/10 rates and notable capacity retention after 100 cycles, compared with cathodes without additives or with carbon black. Further investigations demonstrate the superior performance of the cell incorporating LLTO in a LiNO3-free electrolyte, attributable to the promotion of ion transport and polysulfide adsorption by LLTO, resulting in high discharge capacities (846 mAh g−1 at C/10), efficiency (93–99 %), and stability. Overall, this study compares the effects of electronically and ionically conductive additives on cell performance and highlights the effectiveness of the ionically conductive LLTO. The incorporation of such additives offers innovative solutions to the key challenges for the development of high-performance energy-storage devices.

Optimizing phosphorus-doped polysilicon in TOPCon structures using silicon oxide layers to improve silicon solar cell performance

Tunnel Oxide Passivated Contact (TOPCon) technology is one of the most influential and industrially viable solar cell technologies available today. Improving the quality of passivation contact has become a central focus of current research. Although the conventional monolayer polycrystalline silicon method is highly effective in TOPCon solar cells, it is limited by doping inhomogeneity, which impairs the passivation and electrical properties, and the cell's photovoltaic conversion efficiency remains suboptimal. To address this issue, this study investigates the deposition of two layers of silicon oxide and two layers of in-situ doped phosphorus amorphous silicon, termed double poly-Si/SiOx structures, on n-type silicon wafers using plasma-enhanced chemical vapor deposition (PECVD). The effectiveness of the structure was confirmed through various characterization techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Key findings indicate that the double-polysilicon structure significantly enhances the uniformity of phosphorus doping, improving the carrier lifetime of the cell and reducing the contact resistance. As a result, the average efficiency in the final production stage has a conversion efficiency gain of 0.23 % over the baseline group. This study underscores the potential of this PECVD methodology to advance the fabrication of high-efficiency solar cells by providing significant improvements in passivation, doping uniformity, and overall cell performance.