Composite poly(ethylene oxide)-based solid electrolyte with consecutive and fast ion transport channels constructed by upper-dimensional MIL-53(Al) nanofibers

Novel structural designs for metal organic frameworks (MOFs) are expected to improve ion-transport behavior in composite solid electrolytes. Herein, upper-dimensional MIL-53(Al) nanofibers (MNFs, MIL-53 belongs to the MIL (Material Institute Lavoisier) group) with flower-like nanoflake structures have been designed and constructed via modified hydrothermal coordination. The optimized MNFs with high surface area and porosity can form abundant interfaces with poly(ethylene oxide) (PEO) matrix. The plasticization of MNFs to the PEO matrix will facilitate segmental movement of PEO chains to facilitate Li+ conduction. The unsaturated open metal centers of MNFs can effectively capture bis(trifluoromethanesulfonyl)imide anions (TFSI-) to deliver more free lithium ions for transfer. Moreover, the upper-dimensional nanofiber structure endows lithium ions with a long-range and consecutive transport pathway. The obtained composite solid electrolyte (MNFs@PEO) presents a high ionic conductivity of 4.1 × 10-4 S cm-1 and a great Li+ transference number of 0.4 at 60 °C. The electrolyte also exhibits a stable Li plating/stripping behavior over 1000 h at 0.1 mA cm-1 with inhibited Li dendrite growth. Furthermore, the Li/LiFePO4 and Li/LiNi0.8Mn0.1Co0.1O2 batteries with MNFs@PEO as electrolytes both display great cycling stabilities with high-capacity retention, indicating their potential applications in lithium metal batteries. The study will put forward new inspirations for designing advanced MOF-based composite solid electrolytes.

Enhanced High-Temperature Cycling Stability of Garnet-Based All Solid-State Lithium Battery Using a Multi-Functional Catholyte Buffer Layer

The pursuit of safer and high-performance lithium-ion batteries (LIBs) has triggered extensive research activities on solid-state batteries, while challenges related to the unstable electrode-electrolyte interface hinder their practical implementation. Polymer has been used extensively to improve the cathode-electrolyte interface in garnet-based all-solid-state LIBs (ASSLBs), while it introduces new concerns about thermal stability. In this study, we propose the incorporation of a multi-functional flame-retardant triphenyl phosphate additive into poly(ethylene oxide), acting as a thin buffer layer between LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode and garnet electrolyte. Through electrochemical stability tests, cycling performance evaluations, interfacial thermal stability analysis and flammability tests, improved thermal stability (capacity retention of 98.5% after 100 cycles at 60 °C, and 89.6% after 50 cycles at 80 °C) and safety characteristics (safe and stable cycling up to 100 °C) are demonstrated. Based on various materials characterizations, the mechanism for the improved thermal stability of the interface is proposed. The results highlight the potential of multi-functional flame-retardant additives to address the challenges associated with the electrode-electrolyte interface in ASSLBs at high temperature. Efficient thermal modification in ASSLBs operating at elevated temperatures is also essential for enabling large-scale energy storage with safety being the primary concern.

Engineering and regulating the interfacial stability between Li1.3Al0.3Ti1.7(PO4)3-based solid electrolytes and lithium metal anodes for solid-state lithium batteries

InCl3@Li1.3Al0.3Ti1.7(PO4)3-F (InCl3@LATP-F) solid electrolyte powders are designed and fabricated by coating a uniform InCl3 layer on the surface of F--doped Li1.3Al0.3Ti1.7(PO4)3 (LATP-F) solid powders via a feasible wet-chemical technique. The assembled Li/InCl3@LATP-F/Li cell can undergo longer cycles of 2500 h at 0.4 mA cm-2 without obvious increases in the overvoltage compared to 1837 h for the Li/LATP-F/Li cell, and the interfacial resistance demonstrates a sharp decrease from 3428 to 436 Ω for the Li/InCl3@LATP-F/Li cell during the first 500 h. Importantly, the assembled LiCoO2/InCl3@LATP-F/Li cell delivers a high discharge specific capacity of 126.4 mAh g-1 with a 95.42% capacity retention ratio after 100 cycles at 0.5 C, and the value easily returns to 112.9 mAh g-1 when the current density is abruptly set back to 0.1 C after different rate cycles. These improved results can be mainly attributed to the fact that the InCl3 layer with a lithiophilic nature can react with lithium metal to form a Li-In alloy, which can guarantee homogeneous lithium ion flux to avoid the accumulation of ions/electrons across the interface and suppress the growth of lithium dendrites. Moreover, the InCl3 layer can prevent direct contact of the LATP-F solid electrolyte and lithium metal to effectively alleviate the reduction reaction of Ti4+ and preserve the structural stability of the composite electrolyte. Therefore, this work may provide an effective strategy to engineer and regulate the interfacial stability between LATP solid electrolytes and lithium metal anodes for LATP-type solid-state lithium batteries.

In Situ Gelation of a 1,3-Dioxolane Dual-Permeable Porous Tandem Framework with Excellent Interfacial Stability to Power Long-Cycling Solid-State Lithium Metal Batteries

Ceramic Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) with high ionic conductivity and stability in ambient atmosphere is considered to be potent as a solid-state electrolyte of solid-state lithium metal batteries (SSLMBs), but its huge interfacial impedance with electrodes and the unwanted Ti⁴⁺-mediated reduction reaction caused by the lithium (Li) metal anode greatly limit its application in LMBs. Herein, a composite polymer electrolyte (CPET) was integrated by in situ gelation of dual-permeable 1, 3-dioxolane (DOL) in the tandem framework composed of the commercial cellulose membrane TF4030 and a porous three-dimensional (3D) skeleton-structured LATP. The in situ gelled DOL anchored in the tandem framework ensured nice interfacial contact between the as-prepared CPET and electrodes. The introduction of the porous 3D LATP endowed CPET the increased lithium-ion migration number (t_Li⁺) of 0.70, a wide electrochemical stability window (ESW) of 4.86 V, and a high ionic conductivity of 1.16 × 10^-4 S cm^-1 at room temperature (RT). Meanwhile, the side reaction of the LATP/Li metal was adequately restrained by inserting TF4030 between the porous LATP and Li anode. Profiting from the superb interfacial stability and the enhanced ionic transport capacity of CPET, Li/Li batteries based on the optimal CPET (CPET2) cycled over 2000 h at 20∼30 °C smoothly. Moreover, solid-state LiFePO₄ (LFP)/Li with CPET2 exhibited excellent electrochemical performance with a capacity retention ratio of 72.2% after 400 cycles at 0.5C. This work offers an integrated strategy to guide the fabrication of a highly conductive solid electrolyte and a stable interface design for high-performance SSLMBs.

Tuning the Zn2+ solvation structure in dual-salts hybrid aqueous electrolyte to stabilize the Zn metal anode

Aqueous Zn-ion battery is expected to become a substitute for Li-ion battery due to its inherent safety, low cost, and environmental friendliness. Dendrite growth and side reaction problems during electroplating lead to its low Coulombic efficiency and unsatisfactory life, which greatly limits its practical application. Here, we propose a dual-salts hybrid electrolyte, which alleviates the above issues by mixing Zn(OTf)₂ to ZnSO₄ solution. Extensive tests and MD simulations have shown that the dual-salts hybrid electrolyte can regulate the solvation structure of Zn²⁺, facilitating uniform Zn deposition, and inhibiting side reactions and dendrite growth. Hence, the dual-salts hybrid electrolyte exhibits good reversibility in Zn//Zn batteries, which can provide a lifetime of more than 880 h at 1 mA cm^-2 and 1 mAh cm^-2. Moreover, the average Coulombic efficiency of Zn//Cu cells in hybrid system can reach 98.2% after 520 h, much better than that of 90.7% in pure ZnSO₄ electrolyte and 92.0% in pure Zn(OTf)₂ electrolyte. Benefiting from the fast ion exchange rate and high ion conductivity, Zn-ion hybrid capacitor in hybrid electrolyte also displays excellent stability and capacitive performance. This effective strategy for dual-salts hybrid electrolytes provides a promising direction for designing aqueous electrolytes for Zn-ion batteries.

Constructing LiF/Li2CO3-rich heterostructured electrode electrolyte interphases by electrolyte additive for 4.5 V well-cycled lithium metal batteries

The cycling performance of promising high-voltage Li||LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) batteries is determined by the interfacial stability between electrodes and electrolyte. However, it is challenging to achieve them under high voltage. Herein, we stabilized 4.5 V Li||NCM811 batteries via electrolyte engineering with pentafluorostyrene (PFBE) as the additive. PFBE contributes to the formation of highly Li⁺ conductive and mechanically robust LiF/Li₂CO₃-rich heterostructured interphases on NCM811 cathode and Li metal anode (LMA) surfaces. Such electrode-electrolyte interphases (EEIs) obviously alleviate irreversible phase transition, microcracks induced by stress accumulation and transition metal dissolution in the Ni-rich layered cathode. Meanwhile, the growth of Li dendrites on the LMA surface is effectively controlled. As expected, 4.5 V Li||NCM811 batteries sustain a capacity retention rate of 61.27% after 600 cycles at 0.5 C (100 mA g^-1). More importantly, ∼6.69 Ah Li||NCM811 pouch cells with such electrolytes could represent a stable energy density of ∼485 Wh kg^-1 based on all cell components.

Potassium 2-thienyl tri-fluoroborate as a functional electrolyte additive enables stable interfaces for Li/LiFe0.3Mn0.7PO4batteries

As a promising cathode material for high-performance lithium-ion batteries, olivine LiFe_1-xMn_xPO₄ (0 < x < 1, LFMP) combines the high safety of LiFePO₄ and the high energy density of LiMnPO₄. During the charge-discharge process, poor interface stability of active materials leads to capacity decay, which prevents its commercial application. Here, to stabilize the interface, a new electrolyte additive potassium 2-thienyl tri-fluoroborate (2-TFBP) is developed to boost the performance of LiFe_0.3Mn_0.7PO₄ at 4.5 V vs. Li/Li⁺. Specifically, after 200 cycles, the capacity retention remains at 83.78% in the electrolyte containing 0.2% 2-TFBP while the capacity retention without 2-TFBP addition is only 53.94%. Based on the comprehensive measurements results, the improved cyclic performance is attributed to that 2-TFBP has a higher highest occupied molecular orbit (HOMO) energy and its thiophene group can be electropolymerized above 4.4 V vs. Li/Li⁺ for generating uniform cathode electrolyte interphase (CEI) with poly-thiophene, which can stable materials structure and suppress the decomposition of electrolytes. Meanwhile, 2-TFBP both promotes the deposition/exfoliation of Li⁺ at anode-electrolyte interfaces and regulates Li deposition by K⁺ cations through the electrostatic mechanism. This work presents that 2-TFBP has a great application prospect as a functional additive for high-voltage and high-energy-density lithium metal batteries.

Oriented Zn plating guided by aligned ZnO hexagonal columns realizing dendrite-free Zn metal electrodes

Aqueous zinc-ion batteries (AZIBs), featuring low cost and high safety, have become a research hotspot in recent years. However, the low Zn stripping/plating reversibility, caused by dendritic growth, harmful side reactions, and Zn metal corrosion, severely influences the applicability of AZIBs. Zincophilic materials have shown great potential to form protective layers at the surface of Zn metal electrodes, whereas those protective layers are usually thick, lack fixed crystalline orientation, and require binders. Herein, a facile, scalable, and cost-effective solution method is used to grow vertically aligned ZnO hexagonal columns with (002) top surface and low thickness of 1.3 µm onto Zn foil. Such oriented protective layer can promote homogenous and nearly horizontal Zn plating not only on the top but also at the side of ZnO columns due to the low lattice mismatch between Zn (002) and ZnO (002) facets and between Zn (110) and ZnO (110) facets. Accordingly, the modified Zn electrode exhibits dendrite-free behavior with considerably suppressed corrosion issue, inert byproduct growth, and hydrogen evolution. Thanks to that, the Zn stripping/plating reversibility is significantly improved in Zn//Zn cell, Zn//Ti cell, and Zn//MnO₂ battery. This work provides a promising avenue for guiding metal plating process via oriented protective layer.

Manipulating Interfacial Stability Via Absorption-Competition Mechanism for Long-Lifespan Zn Anode

The stability of Zn anode in various Zn-based energy storage devices is the key problem to be solved. Herein, aromatic aldehyde additives are selected to modulate the interface reactions between the Zn anode and electrolyte. Through comprehensively considering electrochemical measurements, DFT calculations and FEA simulations, novel mechanisms of one kind of aromatic aldehyde, veratraldehyde in inhibiting Zn dendrite/by-products can be obtained. This additive prefers to absorb on the Zn surface than H₂O molecules and Zn²⁺, while competes with hydrogen evolution reaction and Zn plating/stripping process via redox reactions, thus preventing the decomposition of active H₂O near the interface and uncontrollable Zn dendrite growth via a synactic absorption-competition mechanism. As a result, Zn-Zn symmetric cells with the veratraldehyde additive realize an excellent cycling life of 3200 h under 1 mA cm^-2/1 mAh cm^-2 and over 800 h even under 5 mA cm^-2/5 mAh cm^-2. Moreover, Zn-Ti and Zn-MnO₂ cells with the veratraldehyde additive both obtain elevated performance than that with pure ZnSO₄ electrolyte. Finally, two more aromatic aldehyde additives are chosen to prove their universality in stabilizing Zn anodes.

Effect of Janus particles and non-ionic surfactants on the collapse of the oil-water interface under compression

HYPOTHESIS

Janus particles (JPs) and surfactants express different behaviors at the oil-water interface under compression. When both are present at the interface, their synergies result in a different collapse mechanism than when present individually depending on the concentration of the JPs and surfactants.

EXPERIMENTS

Coarse-grained modeling methods were used to probe the synergies between Janus nanoparticles and nonionic surfactants on the stability of an oil-water interface under compression. When both JPs and surfactants were present, the interface was covered at 0-55% area by JPs and contained surfactants at 0-40% of the interfacial surfactant concentration corresponding to the critical micelle concentration (CMC).

FINDINGS

Compression of the interface with only surfactants resulted in the expulsion of surfactant molecules to the water phase once the interfacial concentration of surfactant molecules reached the CMC value. Compression of a Janus particle-laden interface past the closed-packing point led to a buckled interface, so that the total interfacial area remained constant upon further compression. When both surfactants and JPs were present on the interface, JPs still caused buckling, which helped retain the surfactant molecules on the interface. The interface exhibited a higher level of deformation in presence of surfactants. When the surfactant concentration was high, under compression, the surfactants partitioned into the water phase, but the buckling of the interface persisted.

Single-Crystal-Layered Ni-Rich Oxide Modified by Phosphate Coating Boosting Interfacial Stability of Li10 SnP2 S12 -Based All-Solid-State Li Batteries

All-solid-state lithium batteries (ASSLBs) adopting sulfide electrolytes and high-voltage layered oxide cathodes have moved into the mainstream owing to their superior safety and immense potential in high energy density. However, the poor electrochemical compatibility between oxide cathodes and sulfide electrolytes remains a challenge for high-performance ASSLBs. In this study, a nanoscale Li_1.4 Al_0.4 Ti_1.6 (PO₄ )₃ (LATP) phosphate coating is reasonably constructed on the surface of single-crystal LiNi_0.6 Co_0.2 Mn_0.2 O₂ particles to achieve cathode/electrolyte interfacial stability. The conformal LATP layer with inherent high-voltage stability can effectively suppress the oxidation decomposition of the electrolyte and demonstrate chemical inertness to both the oxide cathode and Li₁₀ SnP₂ S₁₂ electrolyte. ASSLBs with an LATP-modified cathode exhibited a high initial discharge capacity (152.1 mAh g^-1 ), acceptable rate capability, and superior cycling performance with a capacity retention of 87.6% after 100 cycles at 0.1 C. Interfacial modification is an effective approach for achieving high-performance sulfide-based ASSLBs with superior interfacial stability.

Stabilizing zinc deposition with sodium lignosulfonate as an electrolyte additive to improve the life span of aqueous zinc-ion batteries

Thanks to high safety and low cost, rechargeable zinc-ion batteries (RZIBs) have become a promising candidate for grid-scale energy storage systems. However, zinc anodes suffer from severe dendrite growth and irreversible side reactions, leading to poor cyclability of RZIBs. In this work, low-cost sodium lignosulfonate (SL) is utilized as the electrolyte additive to solve this problem. The added amount of SL is optimized to be 0.02%, which enables the Zn//α-MnO₂ battery to deliver a large capacity of 146 mAh g^-1 after 1000 cycles at 1 A g^-1, corresponding to a high capacity retention of 83.5%. The Zn//Zn symmetric cell with the modified electrolyte also shows excellent cyclability even under a commercial level of areal specific capacity (4 mAh cm^-2). Overall, the results of this study confirm that the SL additive can improve the ionic conductivity of electrolyte, restrict the two-dimensional planar diffusion of Zn²⁺ ions at the electrode/electrolyte interface, lower the nucleation overpotential of Zn²⁺ ions, prevent side reactions, and inhibit the corrosion of Zn metal. Therefore, the dendrite growth and byproduct formation can be effectively suppressed. This study provides new insights into protecting metal electrodes of electrochemical energy storage devices.

Wheat (Triticum aestivum L.) flour free lipid fractions negatively impact the quality of sponge cake

The functionality of wheat flour lipids in sponge cakes prepared from flour, sugar, eggs and leavening agents only was investigated by altering their location or content in flour. Hexane (hex) or the more polar hexane:isopropanol (3:2 v/v) (hex:isoprop) were used to impact free flour lipid (FFL) or both FFL and bound flour lipid (BFL) fractions, respectively. Flour from which the FFLs were removed resulted in significantly improved cake volumes and crumb structures. Additional removal of part of the BFLs did not further impact cake quality. Prior contact of flour with hex:isoprop followed by gently removing the solvent broke native interactions between BFLs and starch or gluten and relocated more lipids than did hex. Cakes from flour with relocated lipids had coarse crumb structures. Our study demonstrates that FFLs and relocated flour lipids negatively impact sponge cake quality by disturbing air-liquid interface stabilization during mixing and the early phases of baking.