Vol.:(0123456789) https://doi.org/10.1007/s10853-024-10174-w J Mater Sci (2024) 59:17297–17307 Ceramics Ag‑only inner electrode Na0.5Bi0.5TiO3‑based X9R MLCC: achieving high performance and cost efficiency Hamed Salimkhani1,*  , Lovro Fulanović1, Marc Widenmeyer1, and Till Frömling1 1 Department of Materials and Earth Science, Technical University of Darmstadt, Peter‑Grünberg‑Straße 2, 64287 Darmstadt, Germany ABSTRACT The demand for high-power electronic applications is set to drive the neces- sity for robust components like multi-layer ceramic capacitors (MLCCs). These MLCCs must endure a broad temperature range and withstand high electric fields. Simultaneously, the production cost of these components is a crucial con- cern for manufacturers. The regularly used Ag/Pd inner electrodes constitute the most significant cost factor. Hence, this study showcases the fabrication of a sodium bismuth titanate (NBT)-based MLCC using only Ag inner electrodes. This could be achieved by reducing the sintering temperatures with the help of sintering aids, but still maintaining excellent dielectric properties of the ceramic. This MLCC demonstrates an exceptional operational temperature range (− 90 to 310 °C), high energy density (up to 5.1 J/cm3), higher efficiency (92%) at 217 kV/ cm, and robust capacitance stability (variation less than 10%) even under high temperatures and electric fields. Introduction In recent years, considerable efforts have been made in the advancement of high-power applications. Espe- cially, converting energy from renewable sources to electricity is driving the respective demand. Current conversion technology includes semiconductors, notably SiC and GaN Schottky diodes, alongside field-effect transistors (FET) such as metal oxide semi- conductor field-effect transistors (MOSFETs) [1–3]. These semiconductors have showcased resilience and dependability, particularly in demanding operational environments, withstanding temperatures of up to 300 °C and voltages reaching 1700 V [4]. In applica- tions involving the conversion of AC voltage to DC through a rectifier, DC link capacitors are frequently utilized alongside these semiconductors to mitigate ripple voltage [4–7]. Various lead-based capacitors have shown promise [8] but have to be replaced due to the toxicity of lead posed by European Union [9]. As illustrated in Fig. 1, MLCCs feature stacks of alternating layers of dielectric Received: 7 May 2024 Accepted: 29 August 2024 Published online: 23 September 2024 © The Author(s), 2024, cor- rected publication 2025 Handling Editor: David Cann. Address correspondence to E-mail: Hamedsalimkhani25@gmail.com http://orcid.org/0000-0001-7430-0573 http://crossmark.crossref.org/dialog/?doi=10.1007/s10853-024-10174-w&domain=pdf J Mater Sci (2024) 59:17297–17307 demonstrates a temperature-independent permittiv- ity (up to 400 °C) and maintains low tan δ (below 2%) up to a temperature of 350 °C. Furthermore, recent prototype NBT-based MLCCs, though exhibiting impressive stability under varying temperature and electric field conditions, are hindered by their high cost attributed to the use of Pd or Pt as inner electrode materials [43–46]. To address this, a cost-effective alternative involves replacing these expensive electrode materials with more affordable options such as Ag. However, Ag’s significantly lower melting point (961.8 °C) [47] compared to the sinter- ing temperature required for NBT-BT-CZ [42] relaxor material necessitates a reduction in NBT’s sintering temperature. Our previous research has demonstrated that the utilization of specific sintering aids such as Li2O, Bi2O3, and B2O3 successfully reduces the sintering tem- perature of NBT-based solid solutions. Building upon this knowledge, our previous study delves deeper into the effects of these sintering aids on the high-tempera- ture electrical properties of NBT-based solid solutions [48]. The findings unveil minimal adverse effects when these sintering aids are properly engineered. Thus, this study leverages previous knowledge, enhancing NBT’s electrical properties and lowering its sintering temperature, to enable the fabrication of MLCCs based on the NBT-BT-CZ benchmark material with Ag inner electrodes. The outcomes demonstrate outstanding temperature and voltage stability in these MLCCs, alongside excellent reliability and repeatabil- ity, underscoring their cost-effectiveness. Experimental procedure Synthesis The synthesis of the 0.8(0.94[Na0.5Bi0.5Ti(1−x)TaxO3]− 0.06 [BaTi(1−y)TayO3])—0.2CaZr(1−z)TazO3], x = y = z = 0.01, composition was carried out using the conventional solid-state method. Before weighing the powders sourced from Alfa Aesar GmbH, Karlsruhe, Germany, Na2CO3 (99.5%), Bi2O3 (99.975%), BaCO3 (99.8%), and CaCO3 (99.5%) underwent drying at 300 °C. Simul- taneously, TiO2 (99.6%), ZrO2 (99.5%), and Ta2O5 (99.85%) were dried at 800 °C because of their hygro- scopic nature. The purity of the powders was also taken into consideration in the batch calculation. After precise weighing based on the stoichiometric formula, materials and inner metal electrodes connected through external termination electrodes. They show high volumetric efficiency, proving effective in buffer, bypass, alternating-direct current conversion, filtering, and coupling-decoupling applications [10–19]. To meet the new industrial demand for alternative ceramic capacitor materials that operate across a wide range of temperatures from very low to high, and are capable of withstanding high electric fields different types of lead-free ceramic materials have been inves- tigated [15, 20–22]. One commonly used MLCC in the market is based on BaTiO3 (BT) material, which operates effectively only below 130 °C due to its lower Curie temperature [22–24]. Despite efforts to increase BT’s Curie temperature to 200 °C, this improvement falls short of meeting the requirements for harsher environments (temperatures exceeding 200 °C) [25]. As a result, a new class of dielectrics with superior properties has emerged, categorized into two groups: potassium sodium niobate (KNN) [26–31] and sodium bismuth titanate (NBT) [32–37]. Among these, NBT shows promise for the respective capacitor applica- tions [36]. However, integrating NBT solid solutions into industrial MLCC is challenging due to its sensitiv- ity to oxygen vacancy formation during manufactur- ing, resulting in increased electrical conductivity and, thus, higher dielectric loss (tan δ) [35, 38–40]. Addi- tionally, pristine NBT exhibits higher tan δ at lower temperatures, elevated leakage current, and non-pla- teau permittivity (with variations exceeding  ± 15%), thereby failing to meet the criteria for X7R, X8R, and X9R capacitors. To tackle these challenges, prior research has uti- lized solid solutions of NBT with BT [41] and CaZrO3 (CZ) [42]. The NBT-BT-CZ benchmark material Figure 1   Schematic of an MLCC consisting of a dielectric mate- rial (yellow), inner electrodes (orange), and termination elec- trodes (gray). 17298 J Mater Sci (2024) 59:17297–17307 the entire composition was placed in a nylon container filled with ethanol and subjected to 24 h of ball milling in a planetary mill (Pulverisette 5, Fritsch, Germany) at 250 rpm, using yttrium-stabilized zirconia balls. The resulting batch was transferred to a beaker and dried overnight at 100 °C. Next, the dried powder was moved to an alumina crucible and calcined at 900 °C for 3 h, with a heating rate of 5 °C/min. Following this, the calcined powder was milled for an additional 24 h in ethanol using zirconia balls at 250 rpm. After dry- ing the slurries at 100 °C, a mixture of Li2O, Bi2O3, and B2O3 was added into the main powder, with respec- tive weight percentages of 0.100 wt%, 3.106 wt%, and 0.232 wt%. The procedure details are explained in our previous study [48]. MLCC fabrication The process commenced by dispersing 61.84 wt% of the previously acquired powder into a solution con- sisting of 28.09 wt% methyl ethyl ketone (MEK, 99.5%, supplied by Carl ROTH GmbH, Karlsruhe, Germany) and 1.28% oleic acid as the dispersant. This disper- sion was achieved using a planetary ball mill rotat- ing at 100 rpm for approximately 4 h. Subsequently, 3.09 wt% polyethylene glycol (PEG 400, Alfa Aesar) was added as the plasticizer, followed by 5.70 wt% polyvinyl butyral (PVB, Mowital® LP BX 860) as the binder. The mixture underwent overnight milling to attain a homogeneous slurry suitable for tape cast- ing. Tape casting was performed using an automatic machine (Proceq ZAA2300, Switzerland) equipped with adjustable speed and temperature, with a blade gap height set to 200 µm. After drying, tapes with a thickness of approximately 50 µm were obtained. Subsequent to this, the dried tapes underwent screen printing using Ag paste (supplied by Gwent Group, UK), manual cutting, stacking, and pressing using a uniaxial press at a force of approximately 2 kN. Following this, the stacked tapes were subjected to debinding at 400 °C, with a heating rate of 1.0 °C/ min and a dwell time of 2 h, resulting in tapes free of organic material. These tapes were then isostatically pressed at 700 kN and transferred to the furnace for sintering. To prevent any potential delamination of the stacks, the heat treatment commenced up to 600 °C at a heating rate of 1.0 °C/min, followed by a heating rate of 2.5 °C/min up to the sintering temperature (920 °C). A dwell time of 2 h was maintained at the sintering temperature, after which the furnace was allowed to naturally cool down to room temperature. Following sintering, the MLCCs underwent a heat treatment at 600 °C for 2 h. This step aimed to mini- mize the concentration of oxygen vacancies that are thermodynamically favored during the high-temper- ature sintering process. Subsequently, the obtained MLCCs were precisely cut and polished along the edges to expose their inner electrodes, facilitat- ing the establishment of termination contacts. The sintered MLCCs had 5 layers with an active area of ⁓1.5 × 2.6 mm2 and an inner dielectric layer thickness of 125 µm. Characterization The microstructure was assessed using a scanning electron microscope (SEM) equipped with energy- dispersive X-ray spectroscopy (EDX, X-Max80, Oxford Instruments, UK)—JEOL 7600, Japan. High-tempera- ture permittivity (εr) and tan δ data were obtained at 1 kHz through an LCR meter (4284A Precision LCR Meter, Hewlett Packard, USA) connected to a furnace (LE4/11/R6, Nabertherm GmbH, Germany). For low- temperature data (− 115 to 50 °C), the measurements were performed using a Novocontrol Alpha-A High- Performance Frequency Analyzer (Novocontrol Tech- nologies, Germany) and a Quatro Cryosystem (Novo- control Technologies, Germany). Impedance spectroscopy was carried out using the Novocontrol Alpha-A High-Performance Fre- quency Analyzer in the frequency range of 0.1 Hz to 3 MHz, with an amplitude of 0.1 V, covering temper- atures from 125 °C to 600 °C. The resulting imped- ance data underwent analysis using RelaxIS software (rhd instruments, Germany). High-field measure- ments, including dielectric breakdown strengths, were conducted with a TF Analyzer 2000 (aixACCT Systems GmbH, Germany) in a temperature range of 25 °C–125 °C. The capacitance was measured with a small frequency of 1000 Hz and voltage amplitude of 25 V, which was superimposed to a unipolar trian- gular signal of 1 Hz, and the polarization was meas- ured at 1 Hz in triangular signal mode. All samples probed with the TF Analyzer 2000 were immersed in silicone oil (AK 200, Wacker). Thermogravimetric analysis (TGA) was conducted with a NETZSCH STA 449C Jupiter, on the as-prepared tapes in an alumina crucible within air at a flow rate of 50 mL/min and a heating rate of 0.5–10 °C/min from room temperature 17299 J Mater Sci (2024) 59:17297–17307 to 950 °C. The measurement was corrected for buoy- ancy. Optical images were captured using the Zeiss Axio Imager 2 microscope for cross-sectional analysis of the MLCCs. Results and discussion A higher solid load content of a tape significantly contributes to the density after sintering and, conse- quently, to the reliable and enhanced electrical prop- erties of MLCCs. To verify whether the aimed solid content in the tape was achieved, we performed TGA analysis. Figure 2 shows the TGA results for a tape with an aimed powder content of 61.84 wt%. Once the tape is cast, the solvent content evaporates. Therefore, the observed weight loss in the figure pertains to a solvent-free tape. The majority of the weight loss hap- pened between 62 °C and 450 °C. After normalization, the solid content was determined to be approximately 59 wt%, which is close to the target value. The remain- ing 2.84% discrepancy could be attributed to moisture absorbed by the powder during processing, which was likely evaporated during the TGA analysis. During the sintering process, some Ag+ ions may diffuse into the ceramic and act as dopants [49, 50]. It has been shown that Ag can diffuse up to 5 µm into BT during sintering [51]. Due to such a heavy diffusion, Ag ions can migrate, form dendrites, and short-circuit the layers under high electric fields. The challenge is that Ag probably acts as an acceptor dopant in NBT ceramics, which could increase the tan δ and decrease the breakdown strength significantly. We conducted EDX mapping and line scans on the polished cross section (unetched) of the samples, as depicted in Fig. 3 to elucidate the elemental distributions. The mapping encompassed seven elements, including Na, Bi, Ti, Ba, Ca, Zr, and Ag. Figure 3 demonstrates that, within the detection limits of our device, no diffusion of Ag was observed. To closely examine the boundary between Ag and the dielectric, we conducted a line scan cover- ing approximately 8 microns in total both before and after the Ag inner electrode. The results, presented in Fig. 4b, reveal no interdiffusion of Ag into the ceramic within the detection limit of our device, even in areas Figure 2   TGA graph of the as-prepared tape, showing the heat- ing, dwell, and cooling stages in air. Figure 3   The EDX mapping of Ag/MLCC illustrates the distribution of its constituent elements, including Na, Bi, Ti, Ba, Ca, Zr, and Ag, showcasing the spatial arrangement of each element within the material. 17300 J Mater Sci (2024) 59:17297–17307 proximate to the electrode. However, upon entering the electrode area, there is a sharp increase in the Ag concentration, evident from the red profile on the image in Fig. 4b. This does not necessarily imply that it is entirely absent, but rather that it has no significant impact on the properties and falls below the detection limit of the EDS method. Figure  5 illustrates the temperature-dependent characteristics of a bulk and an Ag/MLCC, showcas- ing the relative permittivity (εr) and tan δ at 1 kHz. For both bulk and Ag/MLCC samples, the εr exhib- its a variation within the  ± 15% range (shown in the pink shaded area) over the temperature span of 25 °C–500 °C (bulk) and −100 °C to 474 °C (MLCC), a characteristic typical of capacitors classified as X9R or higher [52]. Moreover, the tan δ remains below 2% in the temperature range of 25 °C–350 °C for bulk (for low-temperature region the reader is referred to [43]) and −90 °C to 310 °C for Ag/MLCCs, surpassing the requirements for X9R capacitors and potentially qualifying for higher designation. The slight differ- ence between the bulk and MLCCs may be attributed to the lower density of the MLCCs after sintering compared to bulk or to the slight diffusion of the Ag electrode into the dielectric material, which, however, could not be detected within the detection limit of our devices. The obtained results are comparable to the work of Ren et al. where they reported the (1−x) Na0.5Bi0.5+yTiO3−xNaTaO3 material system with Bi2O3, CuO, Li2CO3, ZnO, and B2O3 sintering aid composition [53]. Nevertheless, these results exceed those reported by Su et al. for an NBT-based X9R MLCC with Ag/Pd inner electrodes, where a temperature range of − 55 to 205 °C was achieved with tan δ remaining below 2% [52]. Such a stable plateau in εr is of paramount sig- nificance in circuit design for high-power SiC and GaN switching devices, providing designers with excep- tional flexibility, such as the choice of voltage, tem- perature, and capacitance range. The summary of the data derived from this graph is provided in Table 1. Figure 6a illustrates the Nyquist plot of the Ag/ MLCC at 300 °C, spanning the frequency range of Figure 4   a Photographs and dimensions of tested MLCCs. b The EDX line scan of a sin- gle layer of the Ag electrode and its vicinity to observe the potential diffusion of Ag into the dielectric material. Figure 5   The temperature-dependent εr and tan δ of bulk (posi- tive temperature region) and Ag/MLCC (both in positive and negative temperature region) are depicted in the graph. The pink shaded area represents the variations of εr’ ± 15% of the bulk and MLCC, while the red dashed line indicates the maximum tan δ threshold within which industrial capacitors typically operate. Table 1   The maximum εr, tan δ, and operational temperature window of Ag/MLCC at 1 kHz Sample Bulk Ag/MLCC � r ′(max) 635 618 ΔT ( � r � ± 15% ) (°C) 25–500  − 100 to 474 ΔT (tan � ≤ 0.02) (°C) 25–350  − 90 to 310 Frequency (Hz) 1000 1000 17301 J Mater Sci (2024) 59:17297–17307 0.1 Hz to 3 MHz. The semicircle was fitted with a cir- cuit containing a resistor denoted as R. To account for slightly non-ideal capacitive behavior a constant phase element (CPE) was paralleled with R. The careful analysis of the plot demonstrates only one semicircle response. Therefore, only bulk contribution, excluding grain boundary contribution, seems to dominate the electrical response. The fitting results showed a close to an ideal capacitor with an α value of 0.97. To further understand the DC conductivities (σdc) of Ag/MLCCs at various temperatures (in 25 °C increments), fre- quency-dependent σac counterparts were plotted using the real component of the impedance as a function of frequency, and σdc values were then determined by extrapolating low-frequency conductivities to zero frequency similar to the work of Morozov et al. [54]. These values are depicted in Fig. 6b. As illustrated in the figure, at the operating temperature of 150 °C— aligned with the X8R capacitor classification—the σdc is remarkably low, measuring less than 10⁻11 S/cm. As the temperature increases, the conductivity corre- spondingly rises. For example, at the maximum oper- ating temperature of the Ag/MLCC (~ 300 °C), the σdc is estimated to be on the order of 10⁻⁸ S/cm which is comparable to the results of Xu et al. on (1 − x)(0.8Na0. 5Bi0.5TiO3−0.2K0.5Bi0.5TiO3)−xBi(Mg2/3Nb1/3)O3 [55] and Fu et al. on (1 − x)(0.64Na0.5Bi0.5TiO3−0.16 K0.5Bi0.5TiO3− 0.20Bi(Mg2/3Nb1/3)O3)−xCaZrO3 [56] material systems. Figure  7a, b illustrates temperature and field- dependent capacitance and polarization of Ag/MLCC. In Fig. 7a, it is evident that even with an electric field surpassing 200 kV/cm, the capacitance experiences only a slight decrease of 10%. This is a noteworthy accomplishment, as other ferroelectric (FE) or anti- ferroelectric (AFE) materials tend to exhibit a sharp decline or increase under such electric fields, respec- tively [57]. Even though the increase in AFE can be beneficial for obtaining a high energy density, a reli- ably field-independent behavior means better con- trol over the electrical response for multiple applica- tions. Moreover, within this electric field range, the capacitance remains temperature-independent up to the tested temperature (125 °C). Additionally, Fig. 7b reveals that the MLCCs exhibit a relaxor-type behavior with minimal tan δ [58]. Similar to the capacitance- electric field relationship, a temperature-independent Figure 6   a The Nyquist plot of the Ag/MLCC (black semicircle) fitted with an RC circuit (red semicircle) at 300 °C and b an approxima- tion of DC conductivities in the temperature range of 150 °C to 400 °C calculated from the real part of imped- ance plots. Figure 7   Polarization vs. electric field of Ag/MLCC a at room temperature but with a higher maximum applied electric field and b at tem- peratures ranging from 25 °C to 125 °C with an increment of 25 °C at relatively lower electric fields. 17302 J Mater Sci (2024) 59:17297–17307 correlation is observed for polarization vs. electric field. This underscores the robustness and reliability of the fabricated MLCCs. Generally, the aim is to obtain capacitor properties that are frequency-independent over a large frequency range. Figure 8 illustrates the frequency-dependent capacitance of Ag/MLCCs across temperatures rang- ing from 150 °C to 400 °C, in 25 °C increments. As shown, increasing the temperature enhances the sen- sitivity of the MLCCs to frequency; while the capaci- tance exhibits a plateau at 150 °C, it transitions to a parabolic behavior at 400 °C within the frequency range of 0.1–100 kHz. Notably, at 1 kHz, the capaci- tance remains temperature-independent, even at 400 °C. The obtained results are much better than that of BT where the capacitance variation is significantly higher [59]. Furthermore, the Ag/MLCCs demonstrate excellent capacitance stability, maintaining a value of approximately 4 nF at 150 °C up to a frequency of 100 kHz. The capacitance could be simply increased by increasing the number of active layers. Hence, with having the capacitance and DC resistance (obtained from Fig. 6b) available, the time constant (� = RC) was calculated to be 0.58 s at 175 °C. The energy density (wtotal) is a measure of the energy stored per unit volume in a ferroelectric mate- rial under an applied electric field. Energy density is calculated from polarization–electric field (P–E) loops (explained in supporting information). Figure 9a, b illustrates the computed energy densities and efficien- cies plotted against the electric field and temperature, respectively. In Fig. 9a, it is evident that as the electric field increases, the energy density exhibits exponential growth, hitting 5.1 J/cm3 at 217 kV/cm. Moreover, the energy efficiency remains consistently high, exceed- ing 92% across all electric field values. Conversely, Fig. 9b demonstrates the response of energy densities to temperature variations. Remarkably, from 25 °C to 125 °C, both energy density and efficiency not only avoid decline but actually exhibit an increase, show- casing their robust performance across temperature fluctuations. To further contextualize our findings, we com- pared them with the results of Gehringer et al., [43] who used Ag/Pd electrodes (notably more stable than bare Ag electrodes) and NBT-BT-CZ-based materials to construct MLCCs. Their study reported an energy density of approximately 1.1 J/cm3 and an efficiency of 92% at 220 kV/cm at room temperature (2.7 J/cm3 and 86% at 320 kV/cm). In contrast, our work achieved a significantly higher energy density of 5.1 J/cm3 with the same efficiency of 92% at 217  kV/cm at room Figure 8   The frequency-dependent capacitance of Ag/MLCC at temperatures of 150 °C to 400 °C with an increment of 25 °C. Figure 9   The energy density vs. a electric field at 25 °C and b temperature of Ag/MLCC at 200 kV/cm together with their relevant energy efficiencies are depicted. 17303 J Mater Sci (2024) 59:17297–17307 temperature. However, it is worth noting that their study demonstrated a higher dielectric breakdown strength than ours. To ascertain the reliability of our MLCCs, we con- ducted tests on at least 5 samples for energy density, energy efficiency, and dielectric breakdown strength at room temperature. As depicted in Fig. 10a, four out of the five MLCCs exhibited energy densities surpassing 4.5 J/cm3, with MLCC4 reaching a maximum of 5.1 J/ cm3 before experiencing a breakdown. Furthermore, all MLCCs demonstrated energy efficiency exceeding 92%, underscoring the consistency and robustness of our fabricated MLCCs. Additionally, as illustrated in Fig. 10b, the breakdown strength of the samples was evaluated. Four out of five samples exhibited dielectric breakdown strengths exceeding 200 kV/cm, with an average breakdown strength estimated to be 217 kV/ cm. These results further validate the durability and performance of our MLCCs. To shed light on the failure mechanisms underlying the breakdown of the MLCCs, we conducted cross- sectional analyses of several samples (Fig. 11a). As depicted in Fig. 11b, c, d, we identified primarily two distinct failure mechanisms. One failure type originates from the edges of the MLCC (Fig.  11b). Consistent with findings from Figure 10   Repeat- ability tests of the produced MLCCs. a The energy den- sity and energy efficiency and b the dielectric breakdown strengths of the five produced MLCCs. Figure 11   Optical cross-sec- tional images of Ag/MLCC demonstrating a an intact MLCC, b an MLCC failed through local enhancement of the field on the electrode tips, c magnified version of b, and d defects arising from electrode printing and processing. 17304 J Mater Sci (2024) 59:17297–17307 previous studies [60, 61], we observed that electrode tips are particularly susceptible to failure due to the local field enhancements and charge accumulation in these regions [62]. The second failure mode stemmed from the center of the electrode, potentially linked to still present processing defects such as those occur- ring during electrode printing and processing. Thus, there is still some room for optimization toward indus- try relevant processes. However, our cross-sectional examinations revealed no instances of failure attribut- able to Ag-dendrite formation. That means that there is no material-related argument against implement- ing Ag-electrodes for NBT-based MLCC. Hence, being able to exclude Pd for NBT-based components is a large step toward reducing production cost. Conclusion Through meticulous engineering encompassing defect chemistry tailoring and sintering optimization in our previous study [48] and tailored slurry composition, tape casting, and MLCC design in this study, we suc- cessfully produced NBT-based high-power and high- temperature MLCCs with Ag inner electrodes. These are less costly and more environmentally friendly than Ag/Pd electrodes. The MLCCs demonstrate resilience to temperatures reaching 310 °C and electric fields of more than 200 kV/cm. Exposing the material up to 125 °C and high fields simultaneously did not impair the material either. Remarkably, high energy density of up to 5.1 J/cm3 and energy efficiency surpassing 92% at room temperature were achieved. Finally, high repeatability in properties such as energy density, energy efficiency, and dielectric breakdown strength showcased the robustness of the MLCCs. Furthermore, the microstructural analysis revealed no evidence of Ag interdiffusion into the dielectric material, while the observed failure modes aligned with those typical of MLCCs. Overall, this prototype MLCC with Ag-elec- trodes exhibits significant economically and industri- ally, laying the groundwork for the application of even more cost-effective electrode materials in future. Acknowledgements  Hamed Salimkhani and Till Frömling would like to thank the German Ministry of Education and Research (BMBF) for funding the Young Investigator Group HTL-NBT within the program “NanoMatFutur” [Grant No. 03XP0146]. The authors are deeply grate- ful to the Nichtmetallisch-Anorganische Werkstoffe (NAW) group led by Prof. Jürgen Rödel for provid- ing us with the opportunity to conduct experiments in their laboratories. We sincerely appreciate their sup- port and generosity. Funding  Open access funding enabled and organized by Pro- jekt DEAL. Bundesministerium für Bildung und Forschung, 03XP0146, Till Frömling Supplementary Information The online version contains supplementary material available at https://​ doi.​org/​10.​1007/​s10853-​024-​10174-w. Open Access  This article is licensed under a Crea- tive Commons Attribution-NonCommercial-No- Derivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and re- production in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed ma- terial. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Crea- tive Commons licence, unless indicated otherwise in a credit line to the material. 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