Optimum Power Density Research Articles

Optimizing Power Density in Partially Coated Cantilever Beam Energy Harvesters: A Cost-Effective Design Strategy

Optimizing Power Density in Partially Coated Cantilever Beam Energy Harvesters: A Cost-Effective Design Strategy

Using phosphorus doped hydrogenated silicon oxycarbide film as a window layer on the light entrance side of silicon heterojunction solar cells: The role of phase separation on electron transport

The phosphorus doped hydrogenated nanocrystalline silicon oxycarbide (n-nc-SiCO:H) layer can be used as a window layer on the light incident side of silicon heterojunction solar cells (HJT). The chemical composition, structural organization and properties of the n-nc-SiCO:H layer deposited from plasma enhanced chemical vapor deposition (PECVD) method can be easily manipulated via radio frequency power density tuned. Phase separation is observed in the n-nc-SiCO:H layer in which nanoscale silicon crystallites were embedded in amorphous silicon oxycarbide matrix. The optical properties of the n-nc-SiCO:H layer are depended on oxygen and carbon atoms incorporation ratio. The conductivity of the n-nc-SiCO:H layer is dominated by activated phosphorus concentration and the phase separation. The activated phosphorus atoms which play an important role on electron transportation are distributed in both crystalline silicon phase and amorphous silicon phase. Both activated phosphorus concentration and band gap value for oxygen rich amorphous silicon oxycarbide layer are determined by incorporation ratio of O atoms. The interplay effects of optical and electrical properties of the n-nc-SiCO:H layers on HJT cells electric performance variation are revealed out in this report. An average efficiency (across ∼120 cells) of 26.3 % was achieved in cells with optimized power density for the n-nc-SiCO:H layer. The results demonstrate that phase separation in the n-nc-SiCO:H layer plays a critical role on electron transportation.

Experimental study on the low-temperature preheating performance of positive-temperature-coefficient heating film in the prismatic power battery module

The performance of a power battery directly affects the thermal safety performance of the vehicle. Aiming at the improvement of thermal safety of lithium-ion batteries under low temperature condition, this study focuses on the effect of the positive-temperature-coefficient (PTC) heating film on the heating performance of batteries through experimental testing. First, the side and bottom of the cell were heated, and the heat transfer path and mode of the single cell were analyzed. The effects of different power densities and geometric positions on the heating effect were studied by testing the heating time and temperature consistency. Second, for the battery module, a low-temperature heating thermal management heat transfer model was built to analyze the heating mechanism of the heating film under different heating power densities. Finally, the results of these studies were synthesized to obtain the optimal heating power density. The results show that for the cell, the optimum power density of side heating and bottom heating is 0.5 W /cm2 and 0.4 W /cm2, respectively. The time required for side heating from −20 °C to 10 °C is 730 s lower than that of bottom heating, and the maximum temperature difference is 1.885 °C lower. For battery modules, a power density of 0.5 W/cm2 was appropriate for both bottom and side heating methods. Due to the existence of heat conduction between battery packs, the battery modules will be quickly and evenly preheated. Under the optimal power density, the time length for side heating from –20 °C to 10 °C was 1459 s, and the maximum temperature difference was 6.32 °C; bottom heating time required slightly more time (1783 s), and the maximum temperature difference was 6.221 °C. Side heating can be beneficial for the rapid preheating of the battery module. This study will contribute to improving the performance and safety of batteries in cold environments.

Templates-Built Structural Designs for Piezoelectrochemical Pressure Sensors.

Self-powered sensors, capable of detecting static and dynamic pressure without an external power source, are pivotal for advancements in human-computer interaction, health monitoring, and artificial intelligence. Current sensing technologies, however, often fall short of meeting the growing needs for precise and timely pressure monitoring. This article introduces a novel self-powered pressure sensor utilizing electrochemical reactions. The sensor's ion conduction path and internal resistance adjust in response to external stress across a broad range. Its three-dimensional structure, crafted by using a simple template on the electrolyte, enables the efficient and cost-effective detection of various mechanical stimuli. This device not only achieves an optimized power density of approximately 2.34 mW cm-2─surpassing most existing technologies─but also features excellent flexibility, quick response, and recovery times (0.15 and 0.19 s respectively); high durability (2000 cycles); and a broad sensing range (0.23-20 kPa). Moreover, it serves as an ionic touchpad, enhancing data collection and recognition, and integrates seamlessly with a mouthpiece for accurate, real-time monitoring of respiratory activities. This innovative sensor offers minimal cost and simple process requirements while providing multifunctional capabilities for energy harvesting and pressure sensing, marking a significant step forward in the design of next-generation sensors.

Designing nano-heterostructured nickel doped tin sulfide/tin oxide as binder free electrode material for supercapattery

New generation of electrochemical energy storage devices (EESD) such as supercapattery is being intensively studied as it merges the ideal energy density of batteries and optimal power density of supercapacitors in a single device. A multitude of parameters such as the method of electrodes preparation can affect the performance of supercapattery. In this research, nickel doped tin sulfide /tin oxide (SnS@Ni/SnO2) heterostructures were grown directly on the Ni foam and subjected to different calcination temperatures to study their effect on formation, properties, and electrochemical performance through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and electrochemical tests. The optimized SnS@Ni/SnO2 electrode achieved a maximum specific capacity of 319 C g− 1 while activated carbon based capacitive electrode exhibited maximum specific capacitance of 381.19 Fg− 1. Besides, capacitive electrodes for the supercapattery were optimized by incorporating different conductive materials such as acetylene black (AB), carbon nanotubes (CNT) and graphene (GR). Assembling these optimized electrodes with the aid of charge balancing equation, the assembled supercapattery was able to achieve outstanding maximum energy density and power density of 36.04 Wh kg− 1 and 12.48 kW kg− 1 with capacity retention of 91% over 4,000 charge/discharge cycles.

Aircraft Electrothermal Pulse Deicing

Abstract Ice formation and accumulation on aircraft is a major problem in aviation. Icing is directly responsible for aircraft incidents, limiting the safety of air travel and requiring expensive, and sometimes ineffective deicing strategies. Furthermore, electrification of aircraft platforms leads to difficulties with integration of legacy deicing methods such as pneumatic boots. In this work, we study electrothermal pulse deicing capable of efficient and rapid removal of ice from aircraft wings. The pulse approach enables the efficient melting of a thin (<100 μm) ice layer on the wing surface to limit parasitic heat losses. Only the interface is melted, with the rest of the ice sliding on the melt lubrication layer due to aerodynamic forces. To study pulse deicing, we developed a transient thermal-hydrodynamic numerical model that accounts for multiple phases and materials, specific and latent heating effects, melt layer hydrodynamics, as well as boundary layer effects. To identify optimal deicing strategies, we use our model to study the effects of heater thickness (50 μm < th < 1 mm), substrate electrical insulation thickness (10 μm < ti < 1 mm), pulse duration (0.4 s < Δtpulse < 4.5 s), and pulse energy. Optimum operating points are identified for large (Boeing-747), midsize (Embraer-E175), and small (Cessna-172) aircraft. The scale-dependent thermal-hydraulic model results are used to estimate input conditions required for deicing and integrated into an electrical model considering energy storage, power electronics, integration, and layout, to achieve overall volumetric and gravimetric power density optimization.

A two-stage framework for quantifying the impact of operating parameters and optimizing power density and oxygen distribution quality of PEMFC

Proton exchange membrane fuel cell (PEMFC) exhibits significant promise in generating power from hydrogen energy. Operating parameters exert a direct influence on both the power output and the uniformity of oxygen distribution within the PEMFC. Therefore, quantifying the impact of operating parameters and identifying the optimal operating conditions are pivotal to enhance the performance and extend the lifespan of the PEMFC. To this end, a two-stage framework leveraging interpretable machine learning and multi-objective optimization is proposed. In the first stage, an interpretable surrogate model for the PEMFC is established. The impacts of single parameter and pairwise parameters on the power output and the oxygen distribution quality are quantified. Moreover, the decision variables are selected for the second stage. In the second stage, the optimal operating parameters are determined via multi-objective optimization. The results from the first stage suggest that operating voltage and pressure have the highest cumulative contribution for both power density and oxygen distribution quality. The influence mechanism of one operating parameter on the relationship between another operating parameter and the research target is clearly quantified. The findings from the second stage indicate that power density increases by 32 %, 27.36 %, and 32.58 % for three optimized solutions, respectively, while the standard deviation of oxygen molar concentration in the selected operating condition is reduced by 29.66 %.

Simulation and Experimental Research on a New Symmetrical Hydraulic Piezoelectric Energy Harvester

This study introduces a new symmetrical hydraulic piezoelectric energy harvester. By integrating theoretical analysis, simulation, and empirical testing, the research delves into the energy‐harvesting potential of monolithic single‐side output, monolithic two‐side parallel‐connected output, stacked one‐side parallel‐connected output, and stacked two‐side parallel‐connected output under varying parameter configurations. Additionally, it elucidates the energy dissipation occurring during the energy‐harvesting process of stacked piezoelectric disks. It has been observed that the primary determinant of voltage is the amplitude of pulsation, not the static pressure. Concurrently, the study also addresses the consistency of power generation between multiple channels. A study is made on whether there is a proportional relationship between single‐channel power generation and multi‐channel power generation. The root mean square (RMS) voltage of each connection sharply rises with resistance from 2 to 100 KΩ. It is found that the performance of parallel connection of monolithic piezoelectric disk is better than that of other connection methods. At 3 MPa and 100 Hz, the optimal resistance is 16 KΩ, yielding a maximum average power of 1155.63 μW and an optimal power density of 1.774 μW (bar mm3)−1. Consequently, the research offers a novel approach to addressing the issue of sustainable energy supply for low‐power electronic devices and sensors.

Nitrogen-Rich Covalent Organic Frameworks Composited High-Temperature Proton Exchange Membranes with Ultralow Volume Expansion and Reduced Phosphoric Acid Leakage.

Phosphoric acid (PA) leakage and volume expansion are critical factors limiting long-term stable operation of PA-doped polybenzimidazole (PBI) for high-temperature proton exchange membrane fuel cells. Enhancing the interaction between the polymer matrix and PA provides an effective way to minimize PA loss and inhibit excessive membrane swelling. The covalent organic frameworks (COFs) are helpful in improving the performance of PA-PBI membranes due to the robust frameworks, adjustable structures, and good compatibility with polymers. Here, in this work, we synthesized porous COFs named TTA-DFP containing triazine rings and pyridine groups at room temperature for as short as 2 h without oxygen isolation. TTA-DFP was then blended with commercial poly[2,2'-(p-oxidiphenylene)-5,5'-benzimidazole] (OPBI) to prepare composite membranes. The abundant alkaline N sites in TTA-DFP exhibit strong interactions with PA and OPBI, which not only provide more proton transport pathways to promote proton conduction but also immobilize PA in acidophilic micropores to reduce PA leakage. The composite membranes exhibit a much lower volume swelling ratio than that of the OPBI membrane. The PA retention of the composite membrane after 120 h of treatment at 80 °C and 40% relative humidity can reach as high as 84.6%. Particularly, the proton conductivity of the composite membrane doped with 15 wt% TTA-DFP achieves 0.112 S cm-1 at 180 °C without humidification with a swelling ratio of 24.1%. In addition, it has an optimal peak power density of 824.4 mW cm-2 at 180 °C, which is 1.7 times that of the OPBI membrane. The stability of the composite membrane is much better than that of OPBI at a current density of 0.3 A cm-2 at 140 °C for 120 h.

Coaxial MWCNTs/Co-N@N-doped carbon hierarchical porous nanowires as durable air electrode for aqueous Zn-air batteries

Aqueous zinc-air batteries can replace lithium-ion batteries to be used in the future large-scale application. However, efficient bifunctional oxygen catalyst used in air electrode for aqueous zinc-air batteries generally still meet serious challenge. The catalytic activity and stability of air electrode still far from satisfactory. In this work, we designed a series of coaxial MWCNTs/Co-N@N-doped carbon hierarchical porous nanowires (MWCNTs/Co-N@NC) as bifunctional oxygen electrocatalyst with different Co contents. The Co content can facilitate to form the Co-Nx and pyridinic-N to boost the bifunctional oxygen electrocatalysis. The optimal MWCNTs/Co-N@NC-1 delivers superior electrocatalysis for oxygen reduction reaction (ORR) with E1/2 of 0.86 V (vs. RHE) and rational performance for oxygen evolution reaction (OER) with Ej=10 of 1.59 V (vs. RHE) in 0.1 mol/L KOH. In addition, the MWCNTs/Co-N@NC-1-based Zn-air battery exhibits the discharge capacity of 898.84 mAh gZn−1 and a optimal power density of 158.1 mW cm−2 with cycling stability for 300 h. This study provides a strategy to construct robust durability air electrode for aqueous zinc-air batteries.

Integrating physical knowledge and artificial intelligence approaches for simulation and optimization of direct urea fuel cell

Direct urea fuel cell (DUFC) has recently gained attention as a potentially effective fuel cell because of urea’s ease of use, low-cost, high-energy density, and toxicity-free nature. To develop a fast and accurate mathematical tool to model and optimize the performance of DUFC, this study, for the first time, combined the kinetic model and artificial intelligence approaches. Accordingly, an artificial neural network (ANN) model was developed based on the synthetic datasets produced from the verified kinetic model and then was optimized by particle swarm optimization to determine the optimal conditions for DUFC. The peak power density output and substrate-based energy recovery were chosen as the target functions that depend on several fundamental operating and designing parameters (i.e., types of catholyte, membrane thickness, diffusion layer thickness and porosity, feeding flow rate, temperature, urea and KOH concentrations). Along with significantly reducing the computational simulation time to the kinetic model (from 1500 s to 2 s), the proposed approach exhibited superior accuracy compared to the response surface methodology. With nickel nanoparticles as the anode catalyst material and pure oxygen as the catholyte, the highest power density output and energy recovery from DUFC were predicted at 15.1 mW/cm2 and 19.6 %, respectively. On the other hand, with the natural air supply, the optimal power density and energy recovery values were only 14.4 mW/cm2 and 18.9 %, respectively, due to lower oxygen concentration. These poor performances suggest that more efficient catalyst materials for DUFC need to be further investigated and applied.

Synergistic performance of co-precipitated CoCuFe Prussian blue analogue and hydrothermally synthesized V₂C MXene in a solid-state asymmetric supercapacitor

Asymmetric supercapacitors (ASCs) have gained significant attention for their high energy density and extended potential window, ensuring optimal power density. This study presents a solid-state ASC using CoCuFe Prussian blue analogue (PBA) as the positive electrode and hydrothermally grown Vanadium MXene (V2C) as the negative electrode. SEM analysis reveals CoCuFe PBA's coagulated skeleton-like structure and V2C MXene's nanosheet-like morphology. In a three-electrode configuration, CoCuFe PBA shows a specific capacitance of 441 F/g at 0.8 A/g (0 to 0.5 V), while V2C MXene achieves 243 F/g at −1 to 0 V with a 2 M KOH electrolyte. The CoCuFe PBA//V2C ASC device achieves 185 F/g at 1 A/g with a PVA-KOH electrolyte at 1.5 V. This combination facilitates rapid ion diffusion, yielding an energy density of 57.8 Wh/kg and a power density of 1500 W/kg. The device also retains 82 % of its capacitance after 10,000 charge-discharge cycles at 6 A/g, demonstrating excellent stability and potential for high-performance supercapacitors.

Effect of power density on microstructure characterization and fatigue behavior of laser shock peened Rene-80 Ni-based superalloy

The microstructure plays a crucial role in determining the mechanical properties and performance of materials, particularly in high-strength alloys such as Rene-80. This study focuses on the microstructure characterization of Rene-80 nickel-based superalloy after undergoing Laser Shock Peening (LSP), an advanced surface treatment technique imparting beneficial residual stresses and improving fatigue life. The primary objective of this research is to investigate how varying power densities during the LSP process affect the microstructure of the Rene-80 superalloy. The power density in LSP is a critical parameter that influences the intensity of shock waves imparted onto the material’s surface, consequently impacting the microstructure. Through advanced microscopy techniques and analysis, the study explores the resulting microstructural changes, including surface roughness, dislocation density, and the presence of defects like dislocations and dislocation cells. These alterations are vital indicators of the material’s mechanical properties, such as tensile and fatigue strength. LSP samples were characterized using various techniques, including field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) analysis. Additionally, the mechanical performance of the samples was assessed through low-cycle fatigue tests and tensile tests, both conducted before and after LSP treatment. The optimal power density for Laser Shock Peening is determined to be 2.5 HEL. At this power density, the shock wave generated does not create a molten layer on the surface but accumulates defects, resulting in maximum compressive residual stress at the surface. LSP induces intense plastic deformation in the sample, distorting γ’ precipitates. Higher power densities lead to the formation of cross-linked sets of slip bands, highlighting defect slip as the main mechanism of plastic deformation in the LSP process. Understanding these effects is essential for optimizing the LSP process parameters to achieve desired mechanical properties and enhance the performance and longevity of components made from Rene-80 nickel-based superalloy in high-stress applications. It was found that the fatigue life of the samples increased by 500% and optimizing the effect of power density on the LSP process led to an improvement in the fatigue life of the Rene 80 samples.

Electromagnetic–thermal–mass transport triple hybrid model for energy-efficient hydrogen release from metal particles by induction heating

Hydrogen storage in metals is anticipated to be a highly promising technical approach for managing hydrogen in diverse energy applications, emphasizing the need to establish efficient operating conditions. In this study, we developed a numerical model that can simultaneously calculate hydrogen and heat transport combined with electromagnetic induction heating of metal particles. Using the developed numerical simulator, we investigated the behavior of the hydrogen release process from the hydrogen-absorbing metal and proposed important indicators for the operation. The fractions of the electromagnetic energy absorbed by the metal particle used for the hydrogen release, sensible heat, interfacial heat conduction, and thermal radiation were systematically evaluated. Considering the trade-off between temperature rise and the hydrogen concentration gradient, an optimal diameter of metal particles existed for the maximum hydrogen release rate. Similarly, the trade-off between temperature rise and energy consumption revealed an optimal electromagnetic power density for the heat utilization fraction for hydrogen release. Our electromagnetic–thermal–mass transport triple hybrid model constitutes a useful numerical simulator for the design of energy-efficient hydrogen storage systems.

Optimization of thermoelectric generator power density for cryogen cold exergy recovery

The article presents the optimization of the power density of a thermoelectric generator (TEG) operating in cryogenic temperature conditions. Optimization of TEG power density was performed as a function of TEG leg length and its effect on TEG performance. The figure of merit (ZT) of the TEG was experimentally verified for the temperature range of a cold sink from 160 to 250 K, which corresponds to the temperature of the wall subjected to the boiling film of LNG. The numerical model proposed in the article was verified by comparison with experimental data, and then used to simulate the operation of the TEG at a cold sink temperature of 80 K corresponding to the wall temperature in the process of LH2 regasification. The obtained results showed that the optimal length of TEG legs is less than 10 mm and depends on the boiling and heat transfer regime. The results of the presented research can be used to improve the effectivity of cold exergy recovery from cryogenic systems.

Stable, Self‐Adhesive, and High‐Performance Graphene‐Oxide‐Modified Flexible Ionogel Thermoelectric Films

AbstractIonic thermoelectric materials have attracted increasing attention because of their high flexibility and high Seebeck coefficient. However, their insufficient thermoelectric performance and long‐standing processing limit their practical applications. To achieve exotic ionic thermoelectric materials, here, a graphene oxide (GO) modified acrylamide ionogel is designed with high thermoelectric performance and flexibility. Detailed structural characterizations confirm that the uniform dispersion of GO particles in the ionogel structure enables a power factor of 753.0 µW m−1 K−2 and a promising ZT value of 0.19. Additionally, the as‐prepared ionic thermoelectric thin film shows excellent flexibility, stretchability, and self‐adhesiveness. An integrated device, assembled by the as‐prepared ionogel films, can generate an optimal output power density of 1.32 mW cm−2 with a temperature difference of 20 K, indicating great potential for wearable electronics. This work provides insight for searching long‐term, high‐performance ionic thermoelectric materials.

Driver circuit with high-voltage pulse and high-frequency excitation for the cell of optically pumped sensors.

Helium optically pumped sensor is widely used in the application for the detection of weak magnetic fields, and the cell is the core component of that, which needs an external excitation signal to ignite and maintain its luminosity, and its luminosity affects the sensitivity performance of the sensor. To improve the performance of the cell and reduce the power consumption of the system, which is the largest power consumption component in the sensor, this study presents the design of a driver circuit for a helium cell based on a high-voltage pulse source and high-frequency excitation source and uses a T-type impedance matching circuit to realize the efficient transmission of energy. The experimental results demonstrate that the driver circuit can effectively light up the helium cell, in which the pulse voltage of the high-voltage excitation is more than 1.0kV, the output power of the high-frequency excitation signal is in the range of 0-6W, and it is easy to adjust the output power of the high-frequency excitation signal to optimize the sensitivity of the sensor with an the optimal power density of 1.1 W/cm2 and a sensitivity of 29.4 pT/Hz1/2 is obtained. The driver circuit method designed in this study is also suitable for other inert gases to generate metastable atoms.

Utilization of Spent Coffee Grounds for Bioelectricity Generation in Sediment Microbial Fuel Cells.

This study examined the utilization of spent coffee grounds with different aqueous extraction methods for the bioelectricity generation from coastal benthic sediment through a sediment microbial fuel cell (SMFC) system. Different methods for the aqueous extraction of SCGs were evaluated, including rinsing and drying of the SCG (SMFC-CRD), immersion, rinsing and drying (SMFC-CRID), drying alone (SMFC-CD), and untreated SCG (SMFC-C). The caffeine concentration in the SCG was significantly reduced using pretreatments, with SMFC-CRID achieving the lowest concentration of 0.021 ± 0.001 mg/g. SMFC-CRD contributed to the generation of the highest current density of 213.7 mA/m2 during closed-circuit operation and exhibited the highest power density of 96.9 mW/m2 in the polarization test, due to the suitable caffeine content of 0.275 ± 0.001 mg/g in the SCG. This study could provide a cost-effective method for reusing SCGs (i.e., 128 g) while generating bioelectricity as an alternative energy source. These results suggest that pretreatment with SCGs is essential for achieving optimal power density and reducing the caffeine concentration in the SMFC system.

Fabrication of NiO@Ni(OH)2/Graphene Nanosheets//Carbon Electrode as Asymmetric Configuration in Coin Cell Supercapacitor

Electrochemical energy storage devices have emerged as a significant concern for contemporary society global and becoming a devices with great performance are in high demand. Supercapacitors are an alternative that is very suitable for use because of their high-power density, environmentally friendly, long-term cycle, safety, and abundance in nature. NiO and Ni(OH)2 nanoparticles have attracted global attention because of their varied application possibilities and advantages such as low toxicity, low cost, high theoretical capacitance, and environmentally friendly properties. NiO was composited with Ni(OH)2 in this study to enhance the supercapacitor device’s specific capacitance, energy density, and power density. The synthesis of NiO@ Ni(OH)2/Graphene electrodes used a blending method with mass variations of NiO (5, 10, 15, 20, 25) % as active material, and then was characterized using XRD to determine phase constituents and crystal size, SEM to determine morphology, FTIR to test functional groups, Cyclic Voltammetry and Galvanotic Charge-Discharge to test electrochemical properties. The asymmetric coin cell with 15% NiO mass in Ni(OH)2@NiO/ Graphene//Activated Carbon composite has the optimum power density and energy density of 327.4 W/kg and 17.1 Wh/kg.

Study on P-a-Si:H properties of N-type heterogeneous junction solar cells manufactured by large-area parallel plate PECVD machine

P-type hydrogenated amorphous silicon (P-a-Si:H) plays an important role in heterojunction solar cells. On the one hand, P-a-Si:H processed by plasma enhanced vapor deposition (PECVD) can selectively collect carrier holes on the rear of N-type silicon based heterojunctions with intrinsic thin layer (HJT) solar cells (in this article, the back ride of the cell is P-a-Si:H); On the other hand, the ohmic contact between P-a-Si:H and conductive ITO film is beneficial for hole transport. Therefore, the performance of P-a-Si:H has very significant impact on the property of HJT solar cells. The electrical conductivity, impurity activation energy, and passivation performance of silicon wafer surface are the core performance indicators of P-a-Si:H materials themselves. In this paper, we systematically research the optimal RF power density, doping concentration (diborane doped), hydrogen dilution ratio and plate spacing for the growth process of P-a-Si:H using a self-developed large-area parallel plate PECVD equipment (Jincheng Machine). The results show that the P-a-Si:H has an electrical conductivity of 1.27 × 10−3 S/cm and an activation energy of 251 meV, and the maximum mass production efficiency of the HJT solar cell is 25.21%, Voc is 741 mV and Jsc is 41.57 mA/cm2.