Energy Storage Materials最新文献

Liquid metal battery (LMB) is an attractive technology that can address the big challenge of efficient utilization of renewable energies, ascribed to its potential ultralong service lifetime, ideal cost-efficiency, and high safety. However, breaking through the energy density bottleneck remains a persistent challenge, due to the limited lithiation voltage and specific capacity of cathodes. Herein, we design a novel dual-active Sb-Cd cathode, which shows a new ternary alloying discharge mechanism with reversible formation of ternary intermediate phase LiCdSb, accompanied by a high discharge voltage of 1.0 V. Coupled with the excellent Li storage capability of Cd, the Sb₈₀Cd₂₀ cathode attains an attractive capacity (> 500 mAh g^-1), outperforming all reported LMB cathodes. More importantly, upon deep lithiation, the conversion reaction of ternary LiCdSb to Li₃Sb mediates the regeneration and dispersion of Cd melt in the cathode, which constructs in situ fast electron and lithium diffusion networks for the subsequent discharge, significantly accelerating the electrode reaction kinetics. Thus, the Sb₈₀Cd₂₀ electrode achieves an exceptional combination of high energy density (398.4 Wh kg^-1 at 200 mA cm^-2) and superior rate capability (542.5 W kg^-1 at 2400 mA cm^-2). Additionally, the Li||Sb-Cd battery exhibits an outstanding tolerance and self-healing ability towards thermal runaway.

Solid-state potassium-ion batteries (SSPIBs) are recognized as promising energy storage devices due to their cost-effectiveness and high safety. However, the reported SSPIBs generally face low ionic conductivity and poor cycling performance of solid electrolytes. Herein, we report a solid-state composite polymer electrolyte (CPE) by in-situ bridging soft polymer and robust MOF for solid-state potassium-organic batteries (SSPOBs). In this composite structure, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) acts as a soft 3D framework to support both poly ethoxylated trimethylolpropane triacrylate (ETPTA) and UiO-66. The robust UiO-66 anchored through poly (ETPTA) can enhance the mechanical strength and chemical stability to inhibit the dendrites and widen electrochemical window. It can also increase the disorder degree of the polymers to enlarge the activity space of the polymer motion segments, thus improving the ionic conductivity. The plentiful channels inside UiO-66 can allow the transference of K⁺ whereas restrict the ${\text{PF}}_6^{-}$, improving the ionic transference number. The optimized solid-state electrolyte shows a high ionic conductivity (≈3.16×10⁻⁴ S cm⁻¹), a high K⁺ transference number (0.75) and a wide electrochemical window (over 4.5 V). The assembled solid-state potassium-organic batteries (3,4,9,10-perylene-tetracarboxylicacid-dianhydride (PTCDA)|CPE|K) exhibit excellent cycling stability and rate performance, manifesting its feasibility in long-cycling solid-state potassium-ion batteries.

It is a formidable challenge to develop a feasible strategy for the scalable fabrication of all-organic dielectrics with simultaneous improvements in both discharged energy density (U_d) and efficiency (η). Herein, an innovative technology of “melting extrusion-hot stretching-quenching” was put forward for the large-scale preparation of all-organic polymer dielectric films, where polymethyl methacrylate (PMMA) was miscible with polyvinylidene fluoride (PVDF) to form single dispersed phase in the polypropylene (PP) matrix and in-situ transformed into microfibrils with the aid of elongational flow field. Thereby, a simultaneous enhancement in the dielectric constant and breakdown strength was achieved and the as-prepared PP-based all-polymer dielectric film exhibited an unprecedented ultrahigh U_d of 9.6 J cm⁻³ and an exceptional η of 90.9 %. Experimental verification and computational simulation confirmed that the formation of highly oriented PMMA/PVDF microfibrils and well-aligned interfaces are constructive to enhancing breakdown strength by suppressing electric field distortion. The highly oriented dipoles in PVDF and PMMA, coupled with the eliminated ferroelectric behavior of PVDF, synergistically contributed to the heightened U_d and η. The approach presented in this work opens up a promising avenue for the large-scale production of all-organic capacitor films with enhanced U_d and η, heralding a new era of advanced dielectric materials.

The NASICON-type Na₃MnTi(PO₄)₃ material has garnered widespread attention for its stable three-dimensional structure, rapid sodium-ion transport channels and excellent thermal stability. However, its poor electronic conductivity, cyclic stability and structural decay during cycling have posed significant obstacles to its commercialization. Herein, a high-entropy doping Na_3.12MnTi_0.9(VFeMgCrZr)_0.02(PO₄)₃ cathode was successfully synthesized, exhibiting a high reversible capacity of 169.6 mAh g^-1 and a high energy density of over 500 Wh kg^-1. The DFT and machine learning MD results show that benefiting from the high-entropy effect of multi-element synergy in HE-NMTP, the electronic conductivity and sodium ion diffusion kinetics are significantly improved. Simultaneously, the voltage hysteresis and energy loss are mitigated, while crystal structural stability is improved. Furthermore, the full-cell achieves an impressive energy density of 440 Wh kg^-1 (for cathode) at 0.2C. These results demonstrate the advantages of the high-entropy doping cathode as a potential cathode material for sodium-ion batteries and provide a valuable strategy for other NASICON system cathodes as well as polyanion cathodes.

Rechargeable aqueous zinc-ion batteries (ZIBs) are considered ideal candidates for next-generation energy storage systems because of their high safety and cost-effectiveness. However, the widespread adoption depends on the discovery of superior cathode materials. Layered electrode materials, equipped with two-dimensional (2D) ion diffusion channels and tunable layered spacing, have aroused substantial research enthusiasm for their potential applications across diverse energy-related technologies. This review comprehensively presents recent research progress in layered cathode materials tailored for aqueous ZIBs, focusing on layered Mn-based, V-based, and Mo-based cathode materials. It examines their structural characteristics and charge storage mechanisms, highlighting their suitability for electrochemical energy storage. Despite their advantages, challenges associated with the layered structure, such as structural instability, low electrical conductivity, and slow ion transport kinetics, are briefly discussed. Therefore, a spectrum of materials engineering techniques from macroscopic to microscopic levels, are highlighted for their pivotal roles in enhancing electrochemical performance. These include morphological tailoring, conductive additive integrating, heterostructure design, interlayer regulation, defects engineering, and heteroatom doping. In the last part, several prospective research avenues are outlined to guild and catalyze further progress in the development of layered cathode materials for aqueous ZIBs.

Lithium-ion batteries (LIBs) represent an energy storage technology increasingly utilized across various fields. To maintain the safety and reliability of a LIB, monitoring the LIB state of charge (SoC) is essential. Currently, there are limited studies on SoC estimation of cylindrical LIBs using the low-frequency stress wave technique due to its limited sensitivity to internal changes of LIBs during the charging/discharging process. Here, we present the first demonstration of SoC estimation of cylindrical LIBs using low-frequency stress wave (5-50kHz). We adopt Pearson correlation coefficients (PCCs) to select sampling points relevant (>0.5) to the SoC from the response stress wave signals and then apply the multiple random convolutional kernel transform (Multi-Rocket) model to extract four types of features for SoC estimation. The SoC estimation performance of the developed method achieves similar accuracy in both original and down-sampled (low-resolution) signals, with estimation root mean square error of about 0.7%, 1.4%, 3.5%, and 5.3%, respectively in four scenarios. This new method based on low-frequency stress waves enables a drastic cost reduction compared to expensive high-frequency ultrasound methods, paving the way for low-cost, real-time SoC monitoring with excellent accuracy.

Halides are potential electrolytes for Li metal solid state batteries owing to their combination of high ionic conductivity, ductility and electrochemical stability against oxidation. However, their reactivity with the Li metal electrode may result in the formation of secondary compounds hindering their practical utility in terms of cycling performance as key indicator in battery operation. In this work, we investigate the high performance of symmetric cells with Li₃YCl₄Br₂ halide and bare Li-metal electrode, able to withstand 1000 h of Li electrodeposition-dissolution with an overpotential as low as 46 mV. Through a comprehensive analysis employing physico-chemical and electrochemical characterizations, complemented by computational methodologies, we unravel the dynamics of the complex of the Li/halide interface and its evolution during cycling. The reactivity between Li₃YCl₄Br₂ with metallic Li results in the reduction of the halide into LiCl, LiBr and Y metal. Surprisingly, during cycling, those secondary products from the reduction of the halide build a structured solid electrolyte interphase, containing a Y-rich electronic conductive and LiCl and LiBr ionic conductive layers. The particular chemistry and robustness of this solid electrolyte interphase exhibiting a mixed ionic and electronic conductivity appears to be responsible for the outstanding cycling stability.

Sulfur conversion catalysis is an effective strategy to tackle the inherent polysulfide shutting and fast capacity decay in lithium-sulfur batteries. Previous studies identified cobalt phthalocyanine as a unique molecular catalyst with Co-N₄ active sites to promote sulfur reduction reactions. Herein, enhancing the Li bonds with the pyridinic N atoms on the phthalocyanine ligand is demonstrated to endow further catalytic activity in sulfur oxidation reactions. This is enabled by peripheral substitution with electron-donating methoxy groups that strengthens the electronegativity of the pyridinic N atoms. DFT calculations and metadynamics simulations identify the key role of Li bonds in reducing the energy barrier of Li₂S dissociation. The highly lithiophilic methoxy groups also stabilize the dissociated Li cations in their solvation structure. The dissociated S anion can then be oxidized to higher-order polysulfides or radicals by electron donation to the Co-N₄ center, which activates Li₂S for subsequent oxidation. Meanwhile, the catalytic activity in sulfur reduction reactions is also improved by a more efficient electron transfer to adsorbed Li₂S₄, during which the strengthened Li bonds are beneficial in mediating the breakage of the bridging S-S bond. Significant performance improvements are achieved with the bidirectional catalyst under high areal sulfur loading and in Li-S pouch cells.

Aqueous zinc-ion batteries (AZIBs) using organic cathodes have emerged as a sustainable energy storage technology benefitting from high safety, low cost, and abundant feedstocks. However, most organic cathodes are n-type polyaromatic compounds and conjugated polymers, which require sophisticated synthesis, provide a low operational voltage and slow Zn²⁺ diffusion kinetics. Herein, we report access to p-type radical polymer cathodes from a commercially available poly(methyl vinyl ether-alt-maleic anhydride) (poly(MVE-alt-MA)) polymer. The modification of poly(MVE-alt-MA) with 4-amino-TEMPO produces radical polymers (PTEMPO) that are easily scalable to tens of grams. The corresponding polymer AZIBs deliver a capacity of 92 mAh g^-1 at 10 C with 95 % capacity retention over 1000 cycles. Importantly, the electrode composites and battery assembly procedure are optimised so that no fluoro-containing electrolytes and binders are needed, and cheap carbon additives can be used. We assemble the Swagelok batteries, small pouch, and large pouch batteries with a high mass-loading of 7.8 to 50 mg cm^-2, demonstrating nearly 100 % Coulombic efficiency. The pouch battery with 0.8–0.9 g of active polymer displayed a 60-mAh capacity with 1.5 V operational voltage. This work paves the way for simple and practical implementation of polymer AZIBs for real-world applications.

Regulating the lithiophilicity of three-dimensional (3D) lithium hosts is crucial for improving lithium deposition and suppressing dendrite growth. However, previous research has mainly focused on varying lithiophilic components, and the impact of geometric structures induced strain remains poorly understood. Herein, we present a novel curvature-induced strain engineering approach to regulate lithiophilicity and deposition kinetics of lithium in lightweight 3D tubular carbon hosts. A hollow carbon fiber with bilateral growth of MnO₂ nanosheet arrays both inside and outside the tubes (MnO₂@HCFC) have been successfully synthesized. Theoretical calculations and experiments confirm that the MnO₂ layers inside and outside the hollow carbon fiber tube undergo compressive and tensile strain, respectively. The curvatures induced strain modifies the O2p band center of the lithiophilic MnO₂ layer, enabling the regulation of lithiophilicity and preferential and uniform lithium deposition within the carbon fiber tubes. The MnO₂@HCFC framework exhibits excellent lithium affinity and uniform Li⁺ flux distribution, as evidenced by visualization techniques and COMSOL simulations, enabling dendrite-free lithium deposition. The Li-MnO₂@HCFC||LiCoO₂ full cell retains 85.7 % of its capacity after 400 cycles at 0.5 C with a high LiCoO₂ loading of 10.3 mg cm^-2. The optimized lithium anode pouch cell exhibits robust cycle stability under harsh conditions. This work offers new insight into the design of 3D lithium hosts to enhance the performance of lithium anodes through curvature-induced strain engineering.