High Conductivity Research Articles

Coupling thermogalvanic and piezoresistive effects in a robust hydrogel for Deep-Learning-Assisted Self-Powered sign language and object recognition

Coupling thermogalvanic and piezoresistive effects in a robust hydrogel for Deep-Learning-Assisted Self-Powered sign language and object recognition

In51Bi32.5Sn16.5@SiO2 microcapsules-based composite phase change materials with high thermal conductivity and heat storage density for electronics thermal management

Combining phase change microcapsules and various matrix materials can construct novel composite phase change materials (CPCMs). These composite materials hold immense potential for electronics thermal management, owing to their adjustable heat storage capacity and stable shape. Most previous studies focus on enhancing the thermal conductivity of CPCMs by adding thermally conductive fillers or modifying the microcapsule shells. Nevertheless, achieving both high thermal conductivity and heat storage density simultaneously remains a challenge. In this paper, low melting point alloy (In51Bi32.5Sn16.5) was introduced as core material of the microcapsule to enhance the thermal conductivity, due to its significantly higher thermal conductivity compared to commonly used organic or inorganic phase change materials (PCMs). In51Bi32.5Sn16.5@SiO2 microcapsule was synthesized through the sol-gel polymerization method. Furtherly, a form-stable CPCMs consisting of the microcapsules and silicone rubber (SR) matrix were prepared for electronics thermal management. The In51Bi32.5Sn16.5@SiO2 microcapsules exhibit an impressive thermal conductivity of 13.49 Wm−1 K−1, acting as a dual-functional filler for thermal storage and thermal conduction enhancement. Hence, the CPCMs possess a significantly enhanced thermal conductivity of 0.45 Wm−1 K−1, representing a remarkable improvement of 350 % compared to that of pure SR. In addition, the phase change heat storage density of the CPCMs was as high as 71.73 J/cm3. Notable, the prepared CPCMs demonstrate exceptional heat dissipation performance, resulting in a remarkable 23 °C reduction in chip temperature when applied for thermal management. This study offers a novel perspective on the preparation of microcapsule-based CPCMs for electronics thermal management.

Bacterial Cellulose-Based ionogels with synergistically enhanced mechanical and thermoelectric performances for low-grade heat harvesting

Ionogels have a bright prospect for low-grade heat harvesting due to their advantages of non-volatility and high thermal stability. However, it is still challenging to develop ionogels with mechanical robustness and high thermoelectric properties. This work reports a carboxymethylated and Na+ doped bacterial cellulose-based ionogel (CBCIG-Na) with synergistically increased mechanical and thermoelectric performances. The enhancement of thermoelectric properties of ionogels is mainly attributed to the increase of ion transport pathways and the mobility difference between anions and cations in ionic liquid. After the modification, the CBCIG-Na ionogel with 0.5 mol% Na+ (CBCIG-Na0.5%) exhibits high Seebeck coefficient (45.02 mV K−1), ionic conductivity (21.2 mS cm−1) and ionic power factor (4296.82 μW m−1 K−2) when the relative humidity (RH) is 85 %. This is the highest ionic power factor ever reported for bacterial cellulose-based ionogels. Moreover, the CBCIG-Na0.5% shows high tensile strength (7.69 MPa) due to the larger 3D fiber network and enhanced intermolecular force, obvious adhesivity (9.28 kPa) and high transparence (76 %). After that, a flexible i-TE device containing 5 legs and packaged with polydimethylsiloxane (PDMS) was constructed. A high thermovoltage of 264.36 mV is generated when putting the i-TE device (5 legs) on the forearm at room temperature (ΔT = 1.2 K). The outstanding performances, environmentally friendly and low-cost characters of CBCIG-Na0.5% ionogel indicating its great potential for low-grade heat harvesting.

Preparation of thermal interface materials with high thermal conductivity through the synergistic effect of Monoalkoxy-Terminated polysiloxane and branched siloxane oligomers

Four mono-alkoxysilyl-terminated asymmetric siloxane oligomers and a dimethylvinylsilyl-terminated branched-chain structure siloxane oligomer were prepared by a series of reactions to improve the filling loads and dispersion of Al2O3 particles in the polysiloxane matrix. Their influence on the surface modification of Al2O3 particles and the viscosity of composite materials was investigated. When the branched-chain siloxane oligomer was not used, mono-trimethoxysilyl-terminated asymmetric siloxane oligomers exhibited the best modification effect on the Al2O3 surface, and the silicone paste prepared by filling 70.8 vol% mixed-size Al2O3 particles had the lowest viscosity. When the branched-chain siloxane oligomer was used, the filling load of the modified Al2O3 particles could be further increased to 84.3 vol% under the synergistic effect of the mono-trimethoxysilyl-terminated asymmetric siloxane oligomers and the branched-chain siloxane oligomer. The viscosity of the silicone paste decreased with the increase in the polymerization degree of the dimethylsiloxane segment in the-mono trimethoxysilyl-terminated asymmetric siloxane oligomers. Meanwhile, the thermal conductivity of these silicone pastes also exhibited an increasing trend with the increase in the polymerization degree of the asymmetric siloxane oligomers. A thermal interface material with a thermal conductivity higher than 8.0 W/(m·K) was successfully prepared by using the asymmetric siloxane oligomers as the surface modification agent for Al2O3 particles and the branched-chain siloxane oligomer as the fluidity modifier for silicone paste.

Analysis of effect of annealing at high temperature on nickel oxide and zinc oxide thin film for solar cell applications

The use of thin films in solar cell technology has gained substantial interest because of their potential for cost-effective and efficient energy conversion. nickel oxide (NiO) and zinc oxide (ZnO) have been used as potential materials in solar cells application especially third generation solar cells because of their good characteristics, such as high electrical conductivity, chemical stability, resistance to degradation, and abundance and low cost. However, at high temperatures, both NiO and ZnO can undergo thermal decomposition and exhibit crystal defects and grain boundaries. This work investigates high temperature annealing on the morphology, structural, and optical properties of NiO and ZnO thin films. The deposited material was annealed at 500 ℃, 600 ℃, and 700 ℃ and be characterized via scanning electron microscopy (SEM), XRD, and UV-Vi’s spectroscopy. The results showed that inceasing the annealing temperature can improve both ZnO and NiO thin films in structure and appearance. For ZnO, higher temperatures made the grains bigger and more orderly, and for NiO, the process made the grains more organized, bigger in size, and spread out more evenly. However, annealing at high temperature yields a smaller bandgap energy value for both thin films.

Anti-swellable, stretchable, self-healable, shape-memory and supramolecular conductive TA-based hydrogels for amphibious motion sensors

Conductive hydrogel endures as an ideal candidate for flexible electronic devices. However, conventional conductive hydrogels cannot incorporate superior sensitivity under low deformation, biocompatibility and underwater sensing into one system, which widely obstructs their applications in an aqueous environment. Herein, we designed a supramolecular conductive poly(vinyl alcohol) (PVA) and tannic acid (TA) based PVA/TA hydrogel. Due to the effective hydrogen bonding between PVA and TA, the hydrogel possesses some unique properties, including anti-swelling, stretching, self-healing and shape-memory. The PVA/TA supramolecular hydrogel demonstrates an excellent electrical performance where the conductivity and gauge factor (GF) is obtained at 5.5 × 10-4 S/cm and 1.3 in dry and 5.0 × 10-4 S/cm and 1.2 in wet conditions, respectively. The multifunctional hydrogel manifests excellent mechanical properties, where the maximum tensile strength of the hydrogels is 700 kPa at an elongation of 4700 %. Additionally, the hydrogel possesses excellent shape-memory and self-healable properties. Moreover, the hydrogel depicts outstanding biocompatibility, anti-swellable properties and exerts long-term stability underwater to detect human motions. Based on excellent anti-swelling and stability, high electrical conductivity and extraordinary stretching capability, the hydrogels may consider as promising candidates for applications in amphibious motion sensors.

TiH2-based anode: In situ formation of solid electrolyte for high volumetric energy density with minimal content of conducting agent

Herein, we report the fabrication of an electrode composite with an ultra-high active material content (90 wt%). This composite was possible because of the utilization of TiH2 as an anode active material that forms a solid electrolyte (LiH) in situ and functions as an electronic conductor, enabling a substantial reduction of the amount of conductor additive in the electrodes. The electrochemical performance of the TiH2-based electrodes with a high active material content was comparable to that of electrode composites that include a solid electrolyte because of sufficient Li+-ion conduction pathways provided by the LiH formed in situ. To further increase the capacity of the TiH2-based electrode, MgH2 (theoretical capacity: 2036 mAh/g) was mixed with TiH2 to function as an active material. TiH2, which is known to exhibit high electron conductivity and a high density, is expected to be used as a partial substitute for low-density carbon additives to increase the volumetric energy density of batteries and their active material content. Hence, the xMgH2-(1 − x)TiH2-AB (AB: acetylene black) electrode composite exhibited a high active material content (90 wt%) and improved volumetric energy density (1687 Wh/L, based on the anode) compared with a MgH2-AB (70:30 wt%) electrode composite (1157 Wh/L), even when the AB content of the xMgH2-(1 − x)TiH2-AB composite was 10 wt%. In addition, a MgH2-TiH2-VGCF (VGCF: vapor-grown carbon fiber) based electrode composite exhibited the highest volumetric and gravimetric energy density (2154 Wh/L, 1888 Wh/kg) among the investigated composites, facilitated by sufficient electron pathways provided by VGCF.

Electronic transport in nearly compensated half-metallic FeMnGa based-junction

The all-electron full-potential linearized augmented plane-wave method is used to investigate the structural, electronic, and magnetic properties of the cubic C1b FeMnGa. We show that FeMnGa is a spin-gapless semiconductor, and by changing the lattice constant, we obtain a nearly compensated half-metallic ferrimagnet. This makes it suitable for spintronic devices. Then, a combined non-equilibrium Green’s function and density functional theory are used to show that both symmetric and asymmetric FeMnGa/Pd/FeMnGa junctions present infinite giant magneto-resistance, with higher conductance obtained for the symmetric junction with Fe-Pd interfaces.

Poly(phenylene oxide) cross-linked with polybenzimidazole for the applications of high-temperature proton-exchange membrane fuel cells

A series of imidazolium-functionalized poly(phenylene oxide) (QPPO) cross-linked with polybenzimidazole (PBI) (cQPPOx-PBI) membranes were prepared. Compared to the pure PBI membrane without a cross-linked structure nor imidazolium groups, the cQPPOx-PBI membranes showed enhanced toughness, phosphoric acid (PA) retention, and chemical stability. The cQPPOx-PBI membranes showed a enhanced PA uptake than that of PBI membranes, and the cQPPO35-PBI membrane achieves a high conductivity of 139 mS cm−1 at 160 °C, which is much higher than that of PBI membrane under the same conditions (26 mS cm−1). The performance of the single fuel cell assembled with the obtained membranes showed a similar trend as their conductivity, and the cell with cQPPO35-PBI showed a maximum power density of 344 mW cm−2 at 140 °C, while the value for PBI membrane was only 175 mW cm−2 under the same conditions. Herein, a straightforward method was developed for introducing imidazolium groups and cross-linked structures, which can be employed to prepare PEMs with enhanced performance for HT-PEMFCs application.

Enhanced thermal conductivity of epoxy resin by incorporating three-dimensional boron nitride thermally conductive network.

Packaging insulation materials with high thermal conductivity and excellent dielectric properties are favorable to meet the high demand and rapid development of third generation power semiconductors. In this study, we propose to improve the thermal conductivity of epoxy resin (EP) by incorporating a three-dimensional boron nitride thermally conductive network. Detailedly, polyurethane foam (PU) was used as a supporter, and boron nitride nanosheets (BNNSs) were loaded onto the PU supporter through chemical bonding (BNNS@PU). After immersing BNNS@PU into the EP resin, EP-based thermally conductive composites were prepared by vacuum-assisted impregnation. Fourier transform infrared spectrometer and scanning electron microscope were used to characterize the chemical bonding and morphological structure of BNNS@PU, respectively. The content of BNNS in BNNS@PU/EP composites was quantitatively analyzed by TGA. The results show that the thermal conductivity of the BNNS@PU/EP composites reaches 0.521 W/m K with an enhancement rate η of 30.89 at an ultra-low BNNS filler content (5.93 wt. %). Additionally, the BNNS@PU/EP composites have excellent dielectric properties with the frequency range from 101 to 106Hz. This paper provides an interesting idea for developing high thermal conductivity insulating materials used for power semiconductor packaging.

Two-Dimensional Conjugated Metal-Organic Frameworks with a Ring-in-Ring Topology and High Electrical Conductance.

Electrically conducting two-dimensional (2D) metal-organic frameworks (MOFs) have garnered significant interest due to their remarkable structural tunability and outstanding electrical properties. However, the design and synthesis of high-performance materials face challenges due to the limited availability of specific ligands and pore structures. In this study, we have employed a novel highly branched D3h symmetrical planar conjugated ligand, dodechydroxylhexabenzotrinaphthylene (DHHBTN) to fabricate a series of 2D conductive MOFs, named M-DHHBTN (M = Co, Ni, and Cu). This new family of MOFs offers two distinct types of pores, elevating the structural complexity of 2D conductive MOFs to a more advanced level. The intricate tessellation patterns of the M-DHHBTN are elucidated through comprehensive analyses involving powder X-ray diffraction, theoretical simulations, and high-resolution transmission electron microscope. Optical-pump terahertz-probe spectroscopic measurements unveiled carrier mobility in DHHBTN-based 2D MOFs spanning from 0.69 to 3.10 cm2 V-1 s-1. Among M-DHHBTN famility, Cu-DHHBTN displayed high electrical conductivity reaching 0.21 S cm-1 at 298 K with thermal activation behavior. This work leverages the "branched conjugation" of the ligand to encode heteroporosity into highly conductive 2D MOFs, underscoring the significant potential of heterogeneous double-pore structures for future applications.

Ultrathin, Mechanically Durable, and Scalable Polymer-in-Salt Solid Electrolyte for High-Rate Lithium Metal Batteries.

Polymer-in-salt solid-state electrolytes (PIS SSEs) are emerging for high room-temperature ionic conductivity and facile handling, but suffer from poor mechanical durability and large thickness. Here, Al2O3-coated PE (PE/AO) separators are proposed as robust and large-scale substrates to trim the thickness of PIS SSEs without compromising mechanical durability. Various characterizations unravel that introducing Al2O3 coating on PE separators efficiently improves the wettability, thermal stability, and Li-dendrite resistance of PIS SSEs. The resulting PE/AO@PIS demonstrates ultra-small thickness (25µm), exceptional mechanical durability (55.1MPa), high decomposition temperature (330°C), and favorable ionic conductivity (0.12 mS cm-1 at 25°C). Consequently, the symmetrical Li cells remain stable at 0.1mA cm-2 for 3000 h, without Li dendrite formation. Besides, the LiFePO4|Li full cells showcase excellent rate capability (131.0 mAh g-1 at 10C) and cyclability (93.6% capacity retention at 2C after 400 cycles), and high-mass-loading performance (7.5mg cm-2). Moreover, the PE/AO@PIS can also pair with nickel-rich layered oxides (NCM811 and NCM9055), showing a remarkable specific capacity of 165.3 and 175.4 mAh g-1 at 0.2C after 100 cycles, respectively. This work presents an effective large-scale preparation approach for mechanically durable and ultrathin PIS SSEs, driving their practical applications for next-generation solid-state Li-metal batteries.

Characterization of CuAg Alloys with Low Ag Concentrations

Copper-based alloys designed to combine high electronic and thermal conductivities with high mechanical strength find a wide range of applications in different fields. Among the principal representatives, strongly diluted CuAg alloys are of particular interest as innovative materials for the realization of accelerating structures when the use of high-gradient fields requires increasingly high mechanical and thermal performances to overcome the limitations induced by breakdown phenomena. This work reports the production and optical characterization of CuAg crystals at low Ag concentrations, from 0.028% wt to 0.1% wt, which guarantee solid solution hardening while preserving the exceptional conductivity of Cu. By means of Fourier Transform Infrared (FTIR) micro-spectroscopy experiments, the low-energy electrodynamics of the alloys are compared with that of pure Cu, highlighting the complete indistinguishability in terms of electronic transport for such low concentrations. The optical data are further supported by Raman micro-spectroscopy and SEM microscopy analyses, allowing the demonstration of the full homogeneity and complete solubility of solid Ag in copper at those concentrations. Together with the solid solution hardening deriving from the alloying process, these results support the advantage of strongly diluted CuAg alloys over conventional materials for their application in particle accelerators.

Low-Temperature Deposition of Diamond Films by MPCVD with Graphite Paste Additive

Modern integrated circuits (ICs) take advantage of three-dimensional (3D) nanostructures in devices and interconnects to achieve high-speed and ultra-low-power performance. The choice of electrical insulation materials with excellent dielectric strength, electrical resistivity, strong mechanical strength, and high thermal conductivity becomes critical. Diamond possesses these properties and is recently recognized as a promising dielectric material for the fabrication of advanced ICs, which are sensitive to detrimental high-temperature processes. Therefore, a high-rate low-temperature deposition technique for large-grain, high-quality diamond films of the thickness of a few tens to a few hundred nanometers is desirable. The diamond growth rate by microwave plasma chemical vapor deposition (MPCVD) decreases rapidly with lowering substrate temperature. In addition, the thermal conductivity of non-diamond carbon is much lower than that of diamond. Furthermore, a small-grain diamond film suffers from poor thermal conductivity due to frequent phonon scattering at grain boundaries. This paper reports a novel MPCVD process aiming at high growth rate, large grain size, and high sp3/sp2 ratio for diamond films deposited on silicon. Graphite paste containing nanoscale graphite and oxy-hydrocarbon binder and solvent vaporizes and mixes with gas feeds of hydrogen, methane, and carbon dioxide to form plasma. Rapid diamond growth of diamond seeds at 450 °C by the plasma results in large-grained diamond films on silicon at a high deposition rate of 200 nm/h.

Lignin Derived Ultra-Thin All-Solid Polymer Electrolytes with Three dimensional Single-ion Nanofiber Ionic Bridge Framework for High Performance Lithium Batteries.

Solid-state lithium batteries are promising candidates for the next generation high security and high performance batteries. Here, the lignin derived ultra-thin all-solid composite polymer electrolytes (CPEs) with a thickness of only 13.2μm, which possessed three dimensional nanofiber ionic bridge networks composed of single-ion lignin based lithium (L-Li) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) as the framework, and poly(ethylene oxide)/lithium bis(trifluoromethanesulfonyl)imide (PEO/LiTFSI) as the filler, was obtained through electrospinning/spraying and hot-pressing process. The obtained CPE presented high ionic conductivity of 1.3×10-4 S cm-1, excellent oxidative stability of 4.7V, and satisfactory tensile strength of up to 9.30MPa. The Li||Li symmetric cell assembled with the CPE can stably cycle more than 6500h under 0.5mA cm-2 with little Li dendrites growth. Moreover, the assembled Li||CPE||LiFePO4 cells can stably cycle over 700 cycles at 0.2 C with a super high initial discharge capacity of 158.5 mAh g-1 at room temperature, and a favorable capacity of 123 mAh g-1 at -20°C for 250 cycles, and Li||CPE|| NCM can also stably cycle more than 70 cycles with a favorable discharge capacity of 132.4 mAh g-1 at 0.2 C and 30°C. The excellent electrochemical performance was mainly attributed to the reason that the nanofiber ionic bridge network can afford uniformly dispersed single-ion L-Li through electrospinning, which synergized with the LiTFSI well dispersed in PEO to form abundant and efficient three dimensional Li+ transfer channels. Furthermore, the ultra-thin CPE can be compactly attached to the lithium anode, and provided a shorter ion transmission distance between the electrodes, inducing uniform deposition of Li+ at the interface, and inhibiting the lithium dendrites. This work provided a promising strategy to achieve ultra-thin biobased electrolytes with high tensile strength and electrochemical performance for solid-state LIBs. This article is protected by copyright. All rights reserved.

Chitosan Composite Membrane with Efficient Hydroxide Ion Transport via Nano-Confined Hydrogen Bonding Network for Alkaline Zinc-Based Flow Batteries.

The development of membranes with rapid and selective ionic transport is imperative for diverse electrochemical energy conversion and storage systems, including fuel cells and flow batteries. However, the practical application of membranes is significantly hindered by their limited conductivity and stability under strong alkaline conditions. Herein, a unique composite membrane decorated with functional Cu2+ cross-linked chitosan (Cts-Cu-M) is reported and their high hydroxide ion conductivity and stability in alkaline flow batteries are demonstrated. The underlying hydroxide ions transport of the membrane through Cu2+ coordinated nano-confined channels with abundant hydrogen bonding network via Grotthuss (proton hopping) mechanism is proposed. Consequently, the Cts-Cu-M membrane achieves high hydroxide ion conductivity with an area resistance of 0.17Ωcm2 and enables an alkaline zinc-based flow battery to operate at 320mAcm-2, along with an energy efficiency of ≈80%. Furthermore, the membrane enables the battery for 200cycles of long-cycle stability at a current density of 200mAcm-2. This study offers an in-depth understanding of ion transport for the design and preparation of high-performance membranes for energy storage devices and beyond.

Fabrication of thin-film batteries composed of LiCoO2, Li3PO4, and Li layers

AbstractThis paper reports the fabrication of thin-film batteries which are composed of three stacking layers: LiCoO2, Li3PO4, and Li. First, a LiCoO2 layer is constructed on an electron-conductive substrate by pulsed laser deposition as a cathode. The crystallinity of the LiCoO2 layer is mainly controlled by the cationic ratio of Li and Co. Subsequently, an amorphous Li3PO4 layer with a high ionic conductivity is further deposited on the cathode LiCoO2 layer by radio frequency magnetron sputtering as a solid electrolyte. To avoid any possible damage which causes the formation of resistive species between LiCoO2 and Li3PO4, bias control of the substrate during Li3PO4 deposition is essential. Finally, a Li metal layer is deposited as an anode/current collector on the Li3PO4/LiCoO2 bilayer by resistive heating evaporation in a vacuum at an elevated temperature for the formation of a low resistive interface. The fabricated three-layer thin-film battery shows a high-rate capability when the LiCoO2 layer is a (104)-oriented epitaxial film.

Phytic Acid Customized Hydrogel Polymer Electrolyte and Prussian Blue Analogue Cathode Material for Rechargeable Zinc Metal Hydrogel Batteries.

Zinc anode deterioration in aqueous electrolytes, and Zn dendrite growth is a major concern in the operation of aqueous rechargeable Zn metal batteries (AZMBs). To tackle this,the replacement of aqueous electrolytes with a zinc hydrogel polymer electrolyte (ZHPE) is presented in this study. This method involves structural modifications of the ZHPE by phytic acid through an ultraviolet (UV) light-induced photopolymerization process. The high membrane flexibility, high ionic conductivity (0.085Scm-1), improved zinc corrosion overpotential, and enhanced electrochemical stability value of ≈2.3V versus Zn|Zn2+ show the great potential of ZHPE as an ideal gel electrolyte for rechargeable zinc metal hydrogel batteries (ZMHBs). This is the first time that the dominating effect of chelation of phytic acid with M2+ center over H-bonding with water is described to tune the gel electrolyte properties for battery applications. The ZHPE shows ultra-high stability over 360h with a capacity of 0.50mAhcm-2 with dendrite-free plating/stripping in Zn||Zn symmetric cell. The fabrication of the ZMHB with a high-voltage zinc hexacyanoferrate (ZHF) cathode shows a high-average voltage of ≈1.6V and a comparable capacity output of 63mAhg-1 at 0.10Ag-1 of the current rate validating the potential application of ZHPE.

In Situ Construction of a Lithiophilic and Electronically Insulating Multifunctional Hybrid Layer Based on the Principle of Hydrolysis for a Stable Garnet/Li Interface

AbstractAdapting solid‐state Li‐metal batteries is an attractive way to pursue higher energy density and safety compared to liquid‐based ones. With high ionic conductivity and excellent stability with Li, Ta‐doped Li7La3Zr2O12 (LLZTO) is an effective option. However, the poor solid–solid interface contact induced by the lithiophobic Li2CO3 layer hinder its practical application. Herein, a versatile strategy is proposed based on the hydrolysis of sodium tetrafluoroborate (NaBF4), aiming to convert the Li2CO3 into multifunctional hybrid layer containing LiF, LiBO2, and NaF. Among them, LiF and LiBO2 serve as the primary Li ion conductors, the introduction of NaF with high surface energy not only enhances the interface wettability, but also further elevates the critical dendrite strength against Li dendrites. All three components serve as excellent electronic insulators, suppressing electron invasion at the interface and preventing Li dendrite growth in the solid electrolyte. As expected, the interfacial impedance of the NaBF4 treated symmetric cell is reduced to 6.0 Ω cm2, the critical current density (CCD) comes to 2.0 mA cm−2, and cycles over 3000 h at 0.3 mA cm−2 and 1500 h at 0.5 mA cm−2 respectively. Besides, the modified SSBs matched with LiFePO4 or LiNi0.6Co0.2Mn0.2O2 cathode show great long‐term cycling and rate performance.

Elucidation of the Transport Properties of Calcium-Doped High Entropy Rare Earth Aluminates for Solid Oxide Fuel Cell Applications.

Solid oxide fuel cells (SOFCs) are paving the way to clean energy conversion, relying on efficient oxygen-ion conductors with high ionic conductivity coupled with a negligible electronic contribution. Doped rare earth aluminates are promising candidates for SOFC electrolytes due to their high ionic conductivity. However, they often suffer from p-type electronic conductivity at operating temperatures above 500°C under oxidizing conditions caused by the incorporation of oxygen into the lattice. High entropy materials are a new class of materials conceptualized to be stable at higher temperatures due to their high configurational entropy. Introducing this concept to rare earth aluminates can be a promising approach to stabilize the lattice by shifting the stoichiometric point of the oxides to higher oxygen activities, and thereby, reducing the p-type electronic conductivity in the relevant oxygen partial pressure range. In this study, the high entropy oxide (Gd,La,Nd,Pr,Sm)AlO3 is synthesized and doped with Ca. The Ca-doped (Gd,La,Nd,Pr,Sm)AlO3 compounds exhibit a higher ionic conductivity than most of the corresponding Ca-doped rare earth aluminates accompanied by a reduction of the p-type electronic conductivity contribution typically observed under oxidizing conditions. In light of these findings, this study introduces high entropy aluminates as a promising candidate for SOFC electrolytes.