Carbon Energy最新文献

For lithium-sulfur batteries (Li-S batteries), a high-content electrolyte typically can exacerbate the shuttle effect, while a lean electrolyte may lead to decreased Li-ion conductivity and reduced catalytic conversion efficiency, so achieving an appropriate electrolyte-to-sulfur ratio (E/S ratio) is essential for improving the battery cycling efficiency. A quasi-solid electrolyte (COF-SH@PVDF-HFP) with strong adsorption and high catalytic conversion was constructed for in situ covalent organic framework (COF) growth on highly polarized polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) fibers. COF-SH@PVDF-HFP enables efficient Li-ion conductivity with low-content liquid electrolyte and effectively suppresses the shuttle effect. The results based on in situ Fourier-transform infrared, in situ Raman, UV–Vis, X-ray photoelectron, and density functional theory calculations confirmed the high catalytic conversion of COF-SH layer containing sulfhydryl and imine groups for the lithium polysulfides. Lithium plating/stripping tests based on Li/COF-SH@PVDF-HFP/Li show excellent lithium compatibility (5 mAh cm⁻² for 1400 h). The assembled Li-S battery exhibits excellent rate (2 C 688.7 mAh g⁻¹) and cycle performance (at 2 C of 568.8 mAh g⁻¹ with a capacity retention of 77.3% after 800 cycles). This is the first report to improve the cycling stability of quasi-solid-state Li-S batteries by reducing both the E/S ratio and the designing strategy of sulfhydryl-functionalized COF for quasi-solid electrolytes. This process opens up the possibility of the high performance of solid-state Li-S batteries.

Rational design of efficient pH-universal hydrogen evolution reaction catalysts to enable large-scale hydrogen production via electrochemical water splitting is of great significance, yet a challenging task. Herein, Ru atoms in the Ru₂P structure were replaced with M = Co, Ni, or Mo to produce M_2−xRu_xP nanocrystals. The metals show strong site preference, with Co and Ni occupying the tetrahedral sites and Ru the square pyramidal sites of the CoRuP and NiRuP Ru₂P-type structures. The presence of Co or Ni in the tetrahedral sites leads to charge redistribution for Ru and, according to density functional theory calculations, a significant increase in the Ru d-band centers. As a result, the intrinsic activity of CoRuP and NiRuP increases considerably compared to Ru₂P in both acidic and alkaline media. The effect is not observed for MoRuP, in which Mo prefers to occupy the pyramidal sites. In particular, CoRuP shows state-of-the-art activity, outperforming Ru₂P with Pt-like activity in 0.5 M H₂SO₄ (η₁₀ = 12.3 mV; η₁₀₀ = 52 mV; turnover frequency (TOF) = 4.7 s⁻¹). It remains extraordinarily active in alkaline conditions (η₁₀ = 12.9 mV; η₁₀₀ = 43.5 mV) with a TOF of 4.5 s⁻¹, which is 4x higher than that of Ru₂P and 10x that of Pt/C. Further increase in the Co content does not lead to drastic loss of activity, especially in alkaline medium, where, for example, the TOF of Co_1.9Ru_0.1P remains comparable to that of Ru₂P and higher than that of Pt/C, highlighting the viability of the adopted approach to prepare cost-efficient catalysts.

Due to the limitations of the raw materials and processes involved, polyolefin separators used in commercial lithium-ion batteries (LIBs) have gradually failed to meet the increasing requirements of high-end batteries in terms of energy density, power density, and safety. Hence, it is very important to develop next-generation separators for advanced lithium (Li)-based rechargeable batteries including LIBs and Li–S batteries. Nonwoven nanofiber membranes fabricated via electrospinning technology are highly attractive candidates for high-end separators due to their simple processes, low-cost equipment, controllable microporous structure, wide material applicability, and availability of multiple functions. In this review, the electrospinning technologies for separators are reviewed in terms of devices, process and environment, and polymer solution systems. Furthermore, strategies toward the improvement of electrospun separators in advanced LIBs and Li–S batteries are presented in terms of the compositions and the structure of nanofibers and separators. Finally, the challenges and prospects of electrospun separators in both academia and industry are proposed. We anticipate that these systematic discussions can provide information in terms of commercial applications of electrospun separators and offer new perspectives for the design of functional electrospun separators for advanced Li-based batteries.

High electrochemical stability and safety make Na⁺ superionic conductor (NASICON)-class cathodes highly desirable for Na-ion batteries (SIBs). However, their practical capacity is limited, leading to low specific energy. Furthermore, the low electrical conductivity combined with a decline in capacity upon prolonged cycling (>1000 cycles) related to the loss of active material-carbon conducting contact regions contributes to moderate rate performance and cycling stability. The need for high specific energy cathodes that meet practical electrochemical requirements has prompted a search for new materials. Herein, we introduce a new carbon-coated Na₃VFe_0.5Ti_0.5(PO₄)₃ (NVFTP/C) material as a promising candidate in the NASICON family of cathodes for SIBs. With a high specific energy of ∼457 Wh kg⁻¹ and a high Na⁺ insertion voltage of 3.0 V versus Na⁺/Na, this cathode can undergo a reversible single-phase solid-solution and two-phase (de)sodiation evolution at 28 C (1 C = 174.7 mAh g⁻¹) for up to 10,000 cycles. This study highlights the potential of utilizing low-cost and highly efficient cathodes made from Earth-abundant and harmless materials (Fe and Ti) with enriched Na⁺-storage properties in practical SIBs.

Designing high-performance and low-cost electrocatalysts for oxygen evolution reaction (OER) is critical for the conversion and storage of sustainable energy technologies. Inspired by the biomineralization process, we utilized the phosphorylation sites of collagen molecules to combine with cobalt-based mononuclear precursors at the molecular level and built a three-dimensional (3D) porous hierarchical material through a bottom-up biomimetic self-assembly strategy to obtain single-atom catalysts confined on carbonized biomimetic self-assembled carriers (Co SACs/cBSC) after subsequent high-temperature annealing. In this strategy, the biomolecule improved the anchoring efficiency of the metal precursor through precise functional groups; meanwhile, the binding-then-assembling strategy also effectively suppressed the nonspecific adsorption of metal ions, ultimately preventing atomic agglomeration and achieving strong electronic metal-support interactions (EMSIs). Experimental characterizations confirm that binding forms between cobalt metal and carbonized self-assembled substrate (Co–O₄–P). Theoretical calculations disclose that the local environment changes significantly tailored the Co d-band center, and optimized the binding energy of oxygenated intermediates and the energy barrier of oxygen release. As a result, the obtained Co SACs/cBSC catalyst can achieve remarkable OER activity and 24 h durability in 1 M KOH (η₁₀ at 288 mV; Tafel slope of 44 mV dec⁻¹), better than other transition metal-based catalysts and commercial IrO₂. Overall, we presented a self-assembly strategy to prepare transition metal SACs with strong EMSIs, providing a new avenue for the preparation of efficient catalysts with fine atomic structures.

This study explores a symmetric configuration approach in anion exchange membrane (AEM) water electrolysis, focusing on overcoming adaptability challenges in dynamic conditions. Here, a rapid and mild synthesis technique for fabricating fibrous membrane-type catalyst electrodes is developed. Our method leverages the contrasting oxidation states between the sulfur-doped NiFe(OH)₂ shell and the metallic Ni core, as revealed by electron energy loss spectroscopy. Theoretical evaluations confirm that the S–NiFe(OH)₂ active sites optimize free energy for alkaline water electrolysis intermediates. This technique bypasses traditional energy-intensive processes, achieving superior bifunctional activity beyond current benchmarks. The symmetric AEM water electrolyzer demonstrates a current density of 2 A cm⁻² at 1.78 V at 60°C in 1 M KOH electrolyte and also sustains ampere-scale water electrolysis below 2.0 V for 140 h even in ambient conditions. These results highlight the system's operational flexibility and structural stability, marking a significant advancement in AEM water electrolysis technology.

The buried interface in the perovskite solar cell (PSC) has been regarded as a breakthrough to boost the power conversion efficiency and stability. However, a comprehensive manipulation of the buried interface in terms of the transport layer, buried interlayer, and perovskite layer has been largely overlooked. Herein, we propose the use of a volatile heterocyclic compound called 2-thiopheneacetic acid (TPA) as a pre-buried additive in the buried interface to achieve cross-layer all-interface defect passivation through an in situ bottom-up infiltration diffusion strategy. TPA not only suppresses the serious interfacial nonradiative recombination losses by precisely healing the interfacial and underlying defects but also effectively enhances the quality of perovskite film and releases the residual strain of perovskite film. Owing to this versatility, TPA-tailored CsPbBr₃ PSCs deliver a record efficiency of 11.23% with enhanced long-term stability. This breakthrough in manipulating the buried interface using TPA opens new avenues for further improving the performance and reliability of PSC.

The low ion transport is a major obstacle for low-temperature (LT) sodium-ion batteries (SIBs). Herein, a core-shell structure of bismuth (Bi) nanospheres coated with carbon (Bi@C) is constructed by utilizing a novel Bi-based complex (1,4,5,8-naphthalenetetracarboxylic dianhydride as the ligand) as the precursor, which provides an effective template to fabricate Bi-based anodes. At −40°C, the Bi@C anode achieves a high capacity, which is equivalent to 96% of that at 25°C, benefitting from the core-shell nanostructured engineering and Na⁺-ether-solvent cointercalation process. The special Na⁺-diglyme cointercalation behavior may effectively reduce the activation energy and accelerate the Na⁺ diffusion kinetics, enabling the excellent low-temperature performance of the Bi@C electrode. As expected, the fabricated Na₃V₂(PO₄)₃//Bi@C full-cell delivers impressive rechargeability in the ether-based electrolyte at −40°C. Density functional theory calculations and electrochemical tests also reveal the fast reaction kinetic mechanism at LT, thanks to a much lower diffusion energy barrier (167 meV) and a lower reaction activation energy (32.2 kJ mol⁻¹) of Bi@C anode in comparison with that of bulk Bi. This work provides a rational design of Bi-based electrodes for rechargeable SIBs under extreme conditions.

Aqueous zinc-ion batteries have been regarded as the most potential candidate to substitute lithium-ion batteries. However, many serious challenges such as suppressing zinc dendrite growth and undesirable reactions, and achieving fully accepted mechanism also have not been solved. Herein, the commensal composite microspheres with α-MnO₂ nano-wires and carbon nanotubes were achieved and could effectively suppress  ZnSO₄·3Zn(OH)₂·nH₂O rampant crystallization. The electrode assembled with the microspheres delivered a high initial capacity at a current density of 0.05 A g⁻¹ and maintained a significantly prominent capacity retention of 88% over 2500 cycles. Furthermore, a novel energy-storage mechanism, in which multivalent manganese oxides play a synergistic effect, was comprehensively investigated by the quantitative and qualitative analysis for ZnSO₄·3Zn(OH)₂·nH₂O. The capacity contribution of multivalent manganese oxides and the crystal structure dissection in the transformed processes were completely identified. Therefore, our research could provide a novel strategy for designing improved electrode structure and a comprehensive understanding of the energy storage mechanism of α-MnO₂ cathodes.

Solar-driven interfacial evaporation is a promising technology for freshwater production from seawater, but salt accumulation on the evaporator surface hinders its performance and sustainability. In this study, we report a simple and green strategy to fabricate a three-dimensional porous graphene spiral roll (3GSR) that enables highly efficient solar evaporation, salt collection, and water production from near-saturated brine with zero liquid discharge (ZLD). The 3GSR design facilitates energy recovery, radial brine transport, and directional salt crystallization, thereby resulting in an ultrahigh evaporation rate of 9.05 kg m⁻² h⁻¹ in 25 wt% brine under 1-sun illumination for 48 h continuously. Remarkably, the directional salt crystallization on its outer surface not only enlarges the evaporation area but also achieves an ultrahigh salt collection rate of 2.92 kg m⁻² h⁻¹, thus enabling ZLD desalination. Additionally,  3GSR exhibits a record-high water production rate of 3.14 kg m⁻² h⁻¹ in an outdoor test. This innovative solution offers a highly efficient and continuous solar desalination method for water production and ZLD brine treatment, which has great implications for addressing global water scarcity and environmental issues arising from brine disposal.