Symmetric Battery Research Articles

Waterborne Polyurethane Micelles Reinforce PEO-Based Electrolytes for Lithium Metal Batteries.

Although solid polymer electrolytes have been developed for several decades, poly(ethylene oxide) (PEO) or polymers with ethoxy (EO) segments are still one of the most promising candidates for advanced batteries. The low ionic conductivity and lithium-iontransference number as well as the deterioration of mechanical properties after coupling with lithium salts restrict its further adoption. Herein, a serial of PEO-based composite electrolytes optimized by waterborne polyurethane are prepared via blend method. With the assistance of H2O, ionic type waterborne polyurethane assembles into flexible micelles, in which hydrophobic segments as the core and hydrophilic groups as the shell. Utilizing this feature of waterborne polyurethane, PEO and Li salt (LiTFSI) aqueous solution is slowly added to the organic solution of waterborne polyurethane to compoundin situ, and polymer composite electrolytes are fabricated. The multilevel (hydrogen bonds with different binding energy) and multiscale (deformation of flexible micelles) dynamic interaction endows the composite electrolyte with attractive mechanical properties. The assembled Li|Li symmetric battery with the molar ratio of EO to Li salts of 8:1 exhibits excellent cycling stability up to 800 h at 0.1 mA cm-2, and the assembled Li|LiFePO4battery can be stably cycled at 1C for >400 cycles.

Si3N4-Assisted Densification Sintering of Na3Zr2Si2PO12 Ceramic Electrolyte toward Solid-State Sodium Metal Batteries

The solid-state metal battery with solid-state electrolytes has been considered the next generation of energy storage technology owing to its superior safety and high energy density. But, unfavorable ionic conductivity and interfacial problems make it difficult to widely use in practice. In this work, Si3N4 was rationally introduced into the NASICON matrix as a sintering aid, and the influence of Si3N4 on the crystal phase, microstructure, electrochemical and electrical performance of Na3Zr2Si2PO12 (NZSP) ceramic was systematically studied. The results demonstrate that the introduction of Si3N4 can effectively lower the densification sintering temperature of Na3Zr2Si2PO12 electrolyte and enhance the room temperature ionic conductivity of the NZSP to 3.82 × 10−4 S cm−1. In addition, since Si3N4 has a high thermal conductivity and can inhibit the transmission of electrons between the grains of the electrolyte matrix, it will effectively hinder the generation of sodium metal dendrites and relieve the concentration of the heat source. Moreover, owing to the desirable interface compatibility of the Na and NZSP-Si3N4 electrolyte, the Na/NZSP-1150-1%Si3N4/Na symmetric battery exhibits excellent stability, and the electrode/electrolyte interface still maintains good integrity even after long-term cycling. The assembled Na/NZSP-1150-1%Si3N4/Na3.5V0.5Mn0.5Fe0.5Ti0.5(PO4)3 cell manifests an initial specific capacity of 152.5 mA h g−1, together with an initial Coulombic efficiency of 99.8%. Furthermore, after 200 cycles, the battery displays a capacity retention rate of 82%.

In Situ Formation of Stable Dual-Layer Solid Electrolyte Interphase for Enhanced Stability and Cycle Life in All-Solid-State Lithium Metal Batteries.

All-solid-state lithium metal batteries have emerged as a promising solution to overcoming the energy density and safety challenges associated with conventional lithium-ion batteries. Solid polymer electrolytes, particularly those based on poly(vinylidene fluoride) (PVDF) and dimethylformamide (DMF), demonstrate significant potential. However, interfacial side reactions between residual DMF solvents and lithium metal present substantial challenges. In this study, we investigate the in situ formation of solid electrolyte interphase protective layers to mitigate these side reactions. By incorporating F-rich additives, such as fluoroethylene carbonate and lithium difluorophosphate, we successfully establish a dual-layer inorganic SEI structure characterized by an outer LiF layer and an inner Li2O layer. Consequently, our approach extends the cycle life of lithium symmetric batteries to 3000 h. Additionally, the Li||LiFePO4 solid-state battery demonstrates exceptional stability, enduring 400 cycles at a 1C rate with an impressive capacity retention of 84%. This strategic methodology effectively leverages the benefits of residual solvents, ensuring both enhanced battery efficiency and long-term operational stability for PVDF-based all-solid-state lithium metal batteries.

High-Energy-Density All-V2O5 Battery.

Symmetrical batteries hold great promise as cost-effective and safe candidates for future battery technology. However, they realistically suffer low energy density due to the challenge in integrating high specific capacity with high voltage plateau from the limited choice of bipolar electrodes. Herein, a high-voltage all-V2O5 symmetrical battery with clear voltage plateau is conceptualized by decoupling the cathodic/anodic redox reactions based upon the episteme of V2O5intercalation chemistry. As the proof-of-concept, a hierarchical V2O5-carboncomposite (VO-C) bipolar electrode with boosted electron/ion transport kinetics is fabricated, which shows high performance as both cathode and anode in their precisely clamped working potential windows. Accordingly, the symmetrical full-battery exhibits a high capacity of 174 mAh g-1 along with peak voltage output of above 2.9V at 0.5C, remarkable capacity retention of 81% from 0.5C to 10C, and good cycling stability of 70% capacity retention after 300 cycles at 5C. Notably, its energy density reaches 429Wh kg-1 at 0.5C estimated by the cathode mass, which outperforms most of the existing Li/Na/K-based symmetrical batteries. This study leaps forward the performance of symmetrical battery and provides guidance to extend the scope of future battery designs.

Li2CO3/LiF-Rich Solid Electrolyte Interface Stabilized Lithium Metal Anodes for Durable Li-CO2 Batteries

Lithium carbon dioxide (Li-CO2) batteries are considered a promising next-generation energy storage device due to their high theoretical energy density and potential carbon neutralization. Despite numerous iterative advancements in cathode catalysts for Li-CO2 batteries, the cycling stability still to be hindered by the growth of lithium dendrites during cycling, primarily due to uneven deposition and the side reaction of sufficient CO2 with the Li metal anode. In this work, bisalt electrolyte (BE) consisting of LiPF6 and LiTFSI is used as a localized anode surface stabilizer to achieve durable Li-CO2 batteries. The introduction of PF6− promotes the decomposition and reduction of TFSI−, leading to the formation of LiF-rich inorganic SEI (Li2CO3/LiF-rich) with enhanced Li+ affinity and good electronic insulating properties. This effectively inhibits lithium dendrite formation while also insulating CO2 and electrolytes from contacting the lithium anode. Consequently, the Li symmetric battery incorporating the novel BE exhibits a long cycling life of 912 hours (∼3.8 times of the cell with a single-salt electrolyte (SE)). The BE based Li-CO2 battery achieves an ultra-long cyclelife of 2720 hours (∼2.6 times of SE battery) and outstanding rate capability. In addition, the assembled belt-shaped Li-CO2 batteries could stably power a digital watch for 1267 hours.

Enabling high-performance organic copper metal batteries via ultralow-concentration iron ion redox

The stable coordination of chloride ions in aqueous CuCl2 electrolyte results in the coexistence of Cu2+ and Cu+, rendering it a promising electrolyte capable of facilitating various redox reactions. However, the significant challenge arises from the strong combination reaction between aqueous CuCl2 electrolyte and metallic copper, hindering the development of cost-effective copper metal batteries based on variable-valence copper ion electrolytes. Herein, utilizing the synergistic effect of electrolytes, a novel copper metal battery is constructed with a 1 m Cu(OTf)2 + 0.05 m FeCl3 organic electrolyte based on the N-methyl-2-pyrrolidone (NMP) system. Mechanism investigations reveal that the organic electrolyte achieves three-step stable redox reactions in both Cu||PANI battery and Cu||CuFe-PBA battery. Intriguingly, the coordination of ultralow-concentration chloride ions effectively stabilizes Cu+ and enables two independent redox reactions (Cu2+/Cu+ and Cu+/Cu0). Concurrently, ultralow-concentration of Fe3+ facilitates the mutual conversion to Fe2+, which is very rare redox process in electrochemical energy storage. Consequently, the designed organic copper ion electrolyte with 0.05 m FeCl3 additive exhibits outstanding thermodynamic stability towards metallic copper, enabling the Cu||Cu symmetric battery to maintain a cycle lifespan of 4000 h (∼167 days) at 0.5 mA h cm−2, which is the highest one among copper-ion batteries up to date. Benefitting from the redox of Fe3+/Fe2+, the Cu||PANI battery exhibits a high capacity retention of 85.60 % after 2000 cycles. This work opens up unprecedented possibilities of optimizing electrolyte formulations for copper metal batteries.

Economical Se-doped solid-state electrolytes for sodium-ion symmetric batteries

Solid electrolytes, a key component of all solid-state ion batteries, have gained considerable attention for their high safety and chemical stability. Glass-ceramic electrolyte Na3SbS3.6Se0.4 with no grain boundary impedance was obtained through the ball milling method. An ionic conductivity of up to 3.13 m S/cm and a low activation energy of 0.155 eV were realized. It benefited from the partial replacement of S (1.84 Å) by Se (1.98 Å), which has a larger ionic radius than the former, resulting in larger crystals and wider sodium ion migration channels. Na3SbS3.6Se0.4 achieved a large critical current density of 1.443 mA/cm2 and was stable in contact with the anode of the sodium metal sheet. Furthermore, the electrolyte released only 0.046 cm3/g of H2S in a conventional humidity environment for 30 min, which is lower than the 0.09 cm3/g of H2S released by undoped Na3SbS4. All these excellent properties suggest that the designed electrolyte Na3SbS3.6Se0.4 has a high application potential for sodium ions solid batteries.

Enhanced electrochemical performance of garnet Li7La3Zr2O12 electrolyte by efficient incorporation of LiCl

Garnet-type Ta-doped Li7La3Zr2O12 (LLZO) lithium-ion-conducting ceramic electrolytes has become the promising and critical candidate for developing the high-energy-density all-solid-state lithium batteries, due to the satisfied Li+ conductivity, stability against metallic lithium anode, and the feasible preparation under ambient air. Here, to further increase the lithium-ion conductivity of LLZO comparable to that of the commercial organic liquid electrolytes, lithium chloride (LiCl) is effectively introduced to synthesize the garnet-type ceramic electrolytes with the nominal composition (Li6.5La3Zr1.5Ta0.5O12)1-x–(LiCl)x (x = 0, 5mol%, 10mol%, 15mol%, 20mol%, and 25mol%) via high-temperature calcination process. The cubic structure with highly conductive performance is confirmed from X-ray diffraction measurement as well as Raman spectra analysis. Structural information is observed according to field emission scanning electron microscope equipped with energy dispersive spectrometer and density measurements. Among above investigated ceramic compositions, the prepared (Li6.5La3Zr1.5Ta0.5O12)0.85–(LiCl)0.15 ceramic electrolyte sheet sintered at 1200 °C for 12h presents the room-temperature Li-ion conductivity of 1.22 × 10−3 S·cm−1 by alternating current (AC) impedance analysis along with the corresponding activation energy of 0.262eV through Arrhenius equation calculation. The electronic conductivity measurements are also done by direct-current polarization to confirm the ionic nature for all investigated ceramics. Furthermore, the Li|(Li6.5La3Zr1.5Ta0.5O12)0.85–(LiCl)0.15 |Li symmetric batteries can possess the small interfacial resistance of 92.3 Ω cm2 and stably run for 1000 h at 0.1 mA cm−2 without a short circuit at room temperature. The hybridized lithium-sulfur battery with (Li6.5La3Zr1.5Ta0.5O12)0.85–(LiCl)0.15 electrolyte delivered excellent initial room-temperature discharge capacity of 1204mAh·g−1 and 1152 mAh·g−1 under the current density of 0.1C and 0.2C respectively, large coulombic efficiency, and great cycling stability. Moreover, the lithium-sulfur batteries also can show excellent cycling performances under different current densities and a good capacity recoverability. The above investigation results suggest that the low-melting-point LiCl incorporation in Li6.5La3Zr1.5Ta0.5O12 electrolyte is an effective measurement to synthesize the cubic and dense Li-stuff garnet ceramic sheets for the high-performance rechargeable next-generation solid-state batteries.

Electrical Double Layer and In Situ Polymerization SEI Enables High Reversible Zinc Metal Anode.

Aqueous zinc-ion batteries (AZIBs) stand out among new energy storage devices due to their excellent safety and environmental friendliness. However, the formation of dendrites and side reactions on the zinc metal anode during cycling have become the major obstacles to their commercialization. This study innovatively selected Sodium 4-vinylbenzenesulfonate (VBS) as a multifunctional electrolyte additive to address the issues. The dissociated VBS- anions can not only significantly alter the hydrogen bond network structure of H2O in the electrolyte, but also preferentially adsorb on the surface of the zinc anode before H2O molecules, which will result in the development of organic anion-rich interface and alterations to the electrical double layer (EDL) structure. Furthermore, the ─C═C─ structure in VBS leads to the formation of an in situ polymerized organic anion solid electrolyte interface (SEI) layer that adheres to the surface of the zinc anode. The mechanisms work together to significantly improve the performance of Zn//Zn symmetric batteries, achieving a cycle life of over 1800h at 1mA cm-2 and 1 mAh cm-2. The introduction of VBS also enhances the cycling performance and capacity of Zn//δ-MnO2 full cells. This study provides a low-cost solution for the development of AZIBs.

Carboxymethyl Cellulose Gel Electrolyte Based on Hydrolyzed Keratin Modified for Dendrite-Free Zinc-Ion Batteries.

In order to alleviate the dendrite problem of zinc-ion batteries, a gel electrolyte is prepared by Maillard reactions occurring between hydrolyzed wool keratin and carboxymethyl cellulose under heating conditions. The prepared gel electrolyte with the addition of hydrolyzed wool keratin possesses good mechanical properties, and its maximum breaking strength, Young's modulus, and elastic modulus are 58.7, 10.77 MPa, and 157.73 MJ m2, respectively, which are far superior to those of the pure carboxymethyl cellulose gel electrolyte. Because hydrolyzed wool keratin includes amino acids and polypeptides, the ionic conductivity of the prepared gel electrolyte is improved. More importantly, amino and carboxyl groups introduced by hydrolyzed wool keratin contribute to uniform deposition of zinc ions and ease dendrite growth. The assembled symmetric battery was stable for 600 h at a current density of 0.5 mA cm-2 with a capacity of 0.5 mAh cm-2. Combined with a NH4V4O10 cathode, a full battery provides a cycling stability of over 2000 h with a Coulomb efficiency of 98.02%.

Single‐Crystalline Zn(002) Facet Enables Ultrastable Anode–Electrolyte Interface

Dendrite growth and detrimental parasitic side reactions at the anode–electrolyte interface severely restrain the reversibility and cyclability of aqueous zinc‐ion batteries. Due to the lowest surface energy in Zn metal with a hexagonal close‐packed structure, (002) facet can effectively alleviate these side effects. In contrast to several existing works on (002) texturization, single‐crystalline Zn successfully grown using a Bridgman method in this work offers a fundamental understanding on this issue. The perfect atomic arrangement of the low‐surface‐energy (002) cleavage planes, without any grain boundaries, not only kinetically enables an epitaxial deposition inhibiting dendrite formation but also thermodynamically endows the most stable state restraining the side reactions. As a result, the single‐crystalline Zn(002) anode demonstrates a cycling stability over 4800 h (6.7 month) at 2 mA cm−2 in symmetric batteries. Zn(002)//Cu asymmetric batteries achieve a high average Coulombic efficiency of 99.92% over 500 cycles at 10 mA cm−2, enabling a fundamental demonstration of interface engineering for advancing batteries.

Construction of electrospun multistage ZnO@PMIA gel electrolytes for realizing high performance zinc-ion batteries

As an important component of ZIBs, flexible gel electrolytes offer the advantages of solid/liquid electrolytes and good interfacial bonding. However, limited by poor ionic conductivity and mechanical properties, traditional gel electrolytes are still unable to meet realistic applications. To solve the above problems, in this paper, poly(m-phenylene isophthalamide) (PMIA) nanofiber membranes were prepared by electrospinning, and then ordered zinc oxide (ZnO) nanorods were grown on their surfaces by hydrothermal method, and ZnO@PMIA nanofiber membranes were combined with poly(vinyl alcohol) (PVA) gel to obtain ZnO@PMIA-PVA (ZPP) composite electrolytes. On the one hand, thanks to the advantages of large specific surface area and good electrical conductivity of PMIA nanofibers and ZnO nanorods, they can provide continuous and uniform transmission channels for Zn2+ .On the other hand, ZPP combines the nanofiber layer with the gel layer, which possesses excellent mechanical properties and produces a well-bonded interface with the electrode, which can effectively reduce the internal resistance and resist the penetration of the dendrimer into the electrolyte during long cycling. The results show that the ZPP composite electrolyte has a high ionic conductivity (18.3 mS·cm-1) and exhibits obvious advantages in inhibiting hydrogen precipitation and oxidative decomposition of Zn anode, and the Zn/ZPP/Zn symmetric battery can be recycled for >1000 h at 3 mA·cm-2, and the full battery Zn/ZPP/MnO2 can still maintain 159.3 mAh·g-1 residual capacity after 1000 cycles with stable long-cycle performance and high coulombic efficiency (CE) (99 %). This flexible composite electrolyte has high safety, mechanical and electrochemical properties, which can realize high-performance ZIBs, and is expected to provide a new strategy for next-generation wearable energy storage devices.

Low volume fraction co-solvent electrolyte regulates the solvation structure for highly stable zinc-ion batteries

The development of zinc-ion batteries is impeded by parasitic reactions and dendrite formation on Zn anode. In this work, we address these problems using a low volume fraction 2-ethoxyethanol (ECS) co-solvent electrolyte. ECS molecules regulate the solvation structure of Zn2+, promote the generation of a solid electrolyte interphase on the surface of the Zn anode, and play a crucial role in inhibiting parasitic reactions and Zn dendrites. Therefore, the Zn symmetric battery remains stable for 1700 h at 7 mA/cm2 and 7 mA h/cm2. In addition, the Zn||Cu asymmetric battery exhibits stability over 800 cycles at 1 mA/cm2 and 1 mA h/cm2, with an average Coulombic efficiency of 99.54%. Furthermore, the ECS co-solvent electrolyte can significantly enhance the performance of the full cell which achieves higher specific capacity and more stable cycling performance than the one with the aqueous electrolyte.

Improving diffusion kinetics of zinc ions/stabilizing zinc anode by molecular slip mechanism and anchoring effect in supramolecular zwitterionic hydrogels

The severe hydrogen evolution reaction and parasitic side reaction on Zn anode are the key issues which hinder the development of aqueous Zn-based energy storage devices. Herein, a polyacrylamide/carboxylated cellulose nanofibers/betaine citrate supramolecular zwitterionic hydrogels with molecular slip effects are proposed for enhancing Zn2+ diffusion and protecting Zn anodes. Non-covalent interactions within supramolecular hydrogels forms the skeleton for molecular slip and the strong coordination of carboxyl and amino groups with Zn2+ further facilitates the rapid Zn2+ transfer. Additionally, anchoring carboxyl and amino groups at the anode promotes the uniform deposition of Zn2+and protects Zn anode. On the basis of molecular slip mechanism and anchoring effect in the supramolecular zwitterionic hydrogels, Zn||Zn symmetric batteries undergo 800 h of stable electroplating stripping at a depth of discharge of 80 %. Zn||Cu asymmetric batteries exhibit an impressive average coulombic efficiency of 99.4 % over a remarkable span of 900 cycles at a current density of 15 mA cm−2. Furthermore, Zn||NH4V4O10 batteries successfully undergo over 1,000 cycles at a current density of 0.5 A g−1. Intrinsic ion diffusion mechanism of supramolecular hydrogel electrolytes provides an original strategy for the application of high-performance Zn-based energy storage devices.

Investigation of Solid Polymer Electrolytes for NASICON-Type Solid-State Symmetric Sodium-Ion Battery.

The inevitable shift toward renewable energy and electrification necessitates earth-abundant sodium reserves for next-generation Na-based energy storage technologies. By coupling the benefits of solid electrolytes over traditional nonaqueous electrolytes due to their safety hazards, solid-state sodium-ion batteries hold huge prospects in the future. This work presents a comprehensively developed solid-state sodium-ion symmetric full cell operating at room temperature enabled through a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based polymer electrolyte and modified NASICON-structured positive and negative electrodes. Among the investigated polymer electrolytes, PVDF-HFP-NaTFSI was found to outperform other counterparts by achieving a higher ionic conductivity and delivered an appreciable electrochemical stability window. By further delving into the properties of PVDF-HFP-NaTFSI, it was found to possess the least crystallinity, minimal porous structure, lowest melting point, and fusion enthalpy, indicating better ion transport than other investigated polymer electrolytes. The as-assembled solid-state battery revealed a storage capacity of 74 mAh g-1 at 0.1 C with a specific energy density of 130 Wh kgcathode_active_material-1 and demonstrated an impressive capacity retention of 84% of the initial capacity after 200 cycles. The structure and morphology retention of the cycled electrode and electrolyte through postmortem analysis bolster the electrochemo-mechanical stability of the developed solid cell. The findings reported here on polymer electrolytes persuade expedient solutions for developing ambient temperature solid-state sodium-ion batteries with promising electrochemical performance for commercialization in the near future.

Zincophile Zn2+ Conductor Regulation by Ultrathin Nano MoO3 Coating for Dendrite-Free Zn Anode.

Aqueous battery with nonflammable and instinctive safe properties has received great attention. However, issues related to Zn anode such as side reactions and rampant dendrite growth hinder the long-term circulation of AZMBs. Herein, an ultrathin(35nm) MoO3 coating is deposited on the Zn anode by means of vacuum vapor deposition for the first time. Due to the peculiar layer structure of MoO3, insertion of Zn2+ in ZnxMoO3 acts as Zn2+ ion conductor, which regulates Zn2+ deposition in an ordered manner. Additionally, the MoO3 coating can also inhibit the hydrogen evolution and corrosion reactions at the interface. Therefore, both Zn//MoO3@Cu asymmetric battery and Zn symmetric battery cells manage to deliver satisfactory electrochemical performances. The symmetric cell assembled with MoO3@Zn shows a significant long cycle life of more than 1600h at a current density of 2mA cm-2. Meanwhile, the MoO3@Zn//Cu asymmetric cell exhibits an ultrahigh Zn deposition/stripping efficiency of 99.82% after a stable cycling of 650h at 2mA cm-2. This study proposes a concept of "zincophile Zn2+ conductor regulation" to dictate Zn electrodeposition and broadens novel design of vacuum evaporation for nano MoO3 modified Zn anodes.

Enhancing ion conductivity in polyethylene oxide-based polymers through semi-interpenetrating networks with liquid crystalline polymer for lithium metal batteries

Solid electrolytes play a pivotal role in these batteries but are hindered by challenges such as low ion conductivity and inadequate mechanical properties. In this study, a synergistic multi-component system was fabricated using a microphase separation technique to integrate liquid crystal polymers with self-assembly characteristics and polyethylene oxide (PEO) known for its excellent ion transport performance. Molecular-level control was achieved by adjusting the ratio of liquid crystal monomers, facilitating the construction of ordered ion transport pathways that significantly enhance room temperature ion transport efficiency. The resulting solid polymer electrolyte adopts a semi-interpenetrating network structure, where the rigid framework of liquid crystalline polymers is interpenetrated with flexible PEO chains. It exhibits a high room-temperature ion conductivity of 4.7 × 10−4 S/cm and a lithium-ion migration number of 0.71. Benefitting from its tailored microstructure and mechanical properties, the assembled lithium symmetric battery demonstrated stable operation over 2800 h at a room temperature current density of 0.1 mA/cm−2. This research presents a promising pathway for the advancement of advanced electrolyte materials, providing valuable insights into improving the efficiency and safety of lithium metal batteries in practical applications.

Theoretical and experimental studies on 2D β-NiS battery-type electrodes for high-performance supercapacitor

Recently, quirky features and eccentric structures of transition metal sulfides have grasped great attention to remove roadblocks and unwrap fresh avenues for electrodes in energy storage devices. Herein, we developed a 2D beta phase nickel sulfide nanosheets (2D β-NiS NSs) electrode with remarkable enhancement in charge storage properties. When served as active electrodes for electrochemical tests, 2D NiS NSs exhibited ultra-high capacitance of 2693 Fg−1 at 1 mVs−1 and specific capacity of 219 mAhg−1 at 1 Ag−1. The symmetric battery type solid-state supercapacitor device comprising 2D β-NiS NSs electrodes exhibits specific capacity of 83.43 mAhg−1at 2 Ag−1 over broad potential range of 0.7V with good cycling performance, and energy and power density of 28.9 Whkg−1 (@ 2 Ag−1) and 21 kWkg−1 (@ 6 Ag−1) respectively. Complementary first-principles density functional theory (DFT) calculations accomplished to explore the electrolyte ion interactions with nickel sulfide nanostructures defining 2D NiS NSs as a potential candidate for real-time applications.

Assembling Zn2+ on surface of kevlar NanoFibers as functionalized separator for dendrite-free Zn anode and high-performance Zn metal batteries

The proliferation of wearable electronic products has made the development of flexible energy storage devices increasingly important. Among various options, aqueous Zn metal batteries are promising due to their low cost, safety, non-toxicity, environmental friendliness, and abundant element storage. However, the growth of dendrites on the anode surface of Zn metal batteries is a significant challenge to efficient transport of Zn2+, which leads to reduced battery capacity or even failure. This limitation hinders practical applications for these batteries. This study develops a functionalized separator with high ion transport performance and excellent mechanical performances by electrostatic assembling deprotonated PPTA− molecular chains with Zn2+ using Kevlar as a raw material. The successful assembly of Zn2+ is confirmed through chemical composition and functional group analysis. The prepared separator significantly shows the increased the transfer number of Zn2+ and decreased activation energy of Zn2+ deposition. The separator is used in Zn||Zn symmetric batteries, achieving a reversible deposition/stripping process of more than 180 h at a current density of 1 mA cm−2 and a deposition capacity of 1 mAh·cm−2. When applied to Zn||MnO2 batteries, an initial discharging specific capacity of up to 220 mAh·g−1 is obtained at a high current density of 2 A g−1, and the battery could be cycled stably for more than 1, 200 cycles, with a smooth and flat Zn anode surface and no obvious dendrite growth. The separator has good potential for flexible energy storage applications due to its excellent mechanical strength, which enables it to maintain high electrochemical activity even after bending 500 times at 180°. Overall, the functionalized separator effectively inhibits dendrite growth, improves the electrochemical stability of Zn metal batteries, and demonstrates significant application potential for other flexible energy storage applications.

Hydrogen‐Bonded Organic Frameworks‐based Electrolytes with Controllable Hydrogen Bonding Networks for Solid‐State Lithium Batteries

AbstractThe lack of stable solid‐state electrolytes (SSEs) with high‐ionic conductivity and the rational design of electrode/electrolyte interfaces remains challenging for solid‐state lithium batteries. Here, for the first time, a high‐performance solid‐state lithium‐oxygen (Li−O2) battery is developed based on the Li‐ion‐conducted hydrogen‐bonded organic framework (LHOF) electrolyte and the HOF‐DAT@CNT composite cathode. Benefiting from the abundant dynamic hydrogen bonding network in the backbone of LHOF‐DAT SSEs, fast Li+ ion transport (2.2×10−4 S cm−1), a high Li+ transference number (0.88), and a wide electrochemical window of 5.05 V are achieved. Symmetric batteries constructed with LHOF‐DAT SSEs exhibit a stably cycled duration of over 1400 h with uniform deposition, which mainly stems from the jumping sites that promote a uniformly high rate of Li+ flux and the hydrogen‐bonding network structure that can relieve the structural changes during Li+ transport. LHOF‐DAT SSEs‐based Li−O2 batteries exhibit high specific capacity (10335 mAh g−1), and stable cycling life up to 150 cycles. Moreover, the solid‐state lithium metal battery with LHOF‐DAT SSEs endow good rate capability (129.6 mAh g−1 at 0.5 C), long‐term discharge/charge stability (210 cycles). The design of LHOF‐DAT SSEs opens an avenue for the development of novel SSEs‐based solid‐state lithium batteries.