Suppression Of Side Reactions Research Articles

Regulation of Interface Ion Transport by Electron Ionic Conductor Construction toward High-Voltage and High-Rate LiNi0.5Co0.2Mn0.3O2 Cathodes in Lithium Ion Battery.

Simultaneously achieving high-energy-density and high-power-density is a crucial yet challenging objective in the pursuit of commercialized power batteries. In this study, atomic layer deposition (ALD) is employed combined with a coordinated thermal treatment strategy to construct a densely packed, electron-ion dual conductor (EIC) protective coating on the surface of commercial LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode material, further enhanced by gradient Al doping (Al@EIC-NCM523). The ultra-thin EIC effectively suppresses side reactions, thereby enhancing the stability of the cathode-electrolyte interphase (CEI) at high-voltages. The EIC's dual conduction capability provides a potent driving force for Li+ transport at the interface, promoting the formation of rapid ion deintercalation pathways within the Al@EIC-NCM523 bulk phase. Moreover, the strategic gradient doping of Al serves to anchor the atomic spacing of Ni and O within the structure of Al@EIC-NCM523, curbing irreversible phase transitions at high-voltages and preserving the integrity of its layered structure. Remarkably, Al@EIC-NCM523 displays an unprecedented rate capability (114.7 mAh g-1 at 20 C), and a sustained cycling performance (capacity retention of 74.72% after 800 cycles at 10 C) at 4.6V. These findings demonstrate that the proposed EIC and doping strategy holds a significant promise for developing high-energy-density and high-power-density lithium-ion batteries (LIBs).

High‐Performance Zinc Anode Enabled by Zincophilic and Hydrophobic ZnO@Nitrogen‐Doped Carbon/MXene Interface

Aqueous zinc‐ion batteries (AZIBs) are one of the most promising systems for large‐scale energy storage, but their zinc metal anodes suffer from unsatisfactory stability and reversibility due to the uncontrollable Zn dendrite growth and undesirable side reactions. Herein, a ZnO‐anchored nitrogen‐doped carbon/Ti3C2Tx MXene composite (ZnO@NC/MXene) is developed as a protective layer onto the zinc anode, which establishes a zincophilic and hydrophobic interface. In the ZnO@NC/MXene layer, the nitrogen sites efficiently enhances the adsorption of Zn2+, the ZnO provides homogenous nucleation sites for Zn2+ deposition, and the highly conductive MXene ensures even electric field distribution, synergistically inhibiting the zinc dendrites. Additionally, the hydrophobic ZnO@NC/MXene layer suppresses side reactions by limiting contact between the Zn anode and active water. Therefore, the Zn electrode modified by the ZnO@NC/MXene layer shows remarkable stability with a cycle life of over 2600 h in Zn||Zn symmetric cell and outstanding reversibility with an average coulombic efficiency of 99.37% for over 1000 cycles in Zn||Cu asymmetric cell. Coupled with V2O5 cathode, the full cell reveals excellent cycle stability of exceeding 1000 cycles at 4 A g‐1. These results indicate the potential of the zincophilic and hydrophobic ZnO@NC/MXene as a promising interface layer for protecting Zn anode in AZIBs.

Diethylene glycol reduced the water activity of aqueous electrolyte via regulating interphase chemistry for highly durable Zinc-ion batteries

The uncontrollable dendrite growth and parasitic side reactions of Zn lead to poor cycling stability, hindering the practical application of aqueous zinc-ion batteries. Here, we develop a new hybrid electrolyte with zinc trifluoromethanesulfonate dissolved in water and co-solvent diethylene glycol (DEG). DEG can not only alter the Zn2+ solvation structure with the co-participation of DEG and anion to reduce active water molecules, but also interrupt the hydrogen-bond network of the original water. DEG is more easily absorbed on Zn surface than H2O to regulate electric double layer. Based on these unique effects, DEG can regulate interface chemistry, forming a robust solid electrolyte interphase and adjusting Zn2+ stripping/plating behaviors, which suppress side reactions and dendrite growth. Their synergetic effect results in the great improved cycling stability of Zn anode with 5000 h in symmetric cell at 1 mA cm−2 and 1 mAh cm−2. The work shed light on the design of high-performance aqueous electrolyte to advance zinc-ion batteries.

Enhanced battery capacity and cycle life due to suppressed side reactions on the surface of Ni-rich LiNi0.8Co0.1Mn0.1O2 cathode materials coated with Co3(PO4)2

This study explores a strategy to mitigate capacity fading in secondary batteries, which is primarily attributed to side reactions caused by residual Li impurities (LiOH or Li2CO3) on the surface of Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) layered cathode materials. By applying a 1.5 wt% Co3(PO4)2 coating, we successfully formed a thin and stable LiF cathode-electrolyte interface (CEI) layer, which resulted in decreased battery resistance and enhanced diffusion of Li+ ions within the electrolyte. This coating significantly improved the interface stability of NCM811, leading to superior battery performance. Specifically, the discharge capacity of uncoated NCM811 was 190 mA h g−1 at a charge of 4.3 V and a rate of 0.1C, whereas the 1.5Co3(PO4)2/NCM811 exhibited an increased capacity of 213 mA h g−1. Furthermore, the Co3(PO4)2 coating effectively reduced the levels of LiOH and Li2CO3 on the NCM811 surface to only 0.1 %, thereby minimizing adverse side reactions with the electrolyte salt (LiPF6), cation mixing between Ni2+ and Li+, and defects at the NCM811 interface. As a result, battery lifespan was significantly extended. This study presents a robust approach for enhancing battery stability and performance by efficiently reducing residual Li+ ions on the surface of NCM811 through strategic Co3(PO4)2 coating.

Achieving Dendrite-Free and By-Product-Free Aqueous Zn-Ion Battery Anode via Nicotinic Acid Electrolyte Additive with Molecule-Ion Conversion Mechanism.

The widespread adoption of aqueous Zn ion batteries is hindered by the instability of the Zn anode. Herein, an elegant strategy is proposed to enhance the stability of Zn anode by incorporating nicotinic acid (NA), an additive with a unique molecule-ion conversion mechanism, to optimize the anode/electrolyte interface and the typical ZnSO4 electrolyte system. Experimental characterization and theoretical calculations demonstrate that the NA additive preferentially replaces H2O in the original solvation shell and adsorbs onto the Zn anode surface upon conversion from molecule to ion in the electrolyte environment, thereby suppressing side reactions arising from activated H2O decomposition and stochastic growth of Zn dendrites. Simultaneously, such a molecule-to-ion conversion mechanism may induce preferential deposition of Zn along the (002) plane. Benefiting from it, the Zn||Zn symmetric battery cycles stably for 2500h at 1mAcm-2, 1mAhcm-2. More encouragingly, the Zn||AC full batteries and the Zn||AC full batteries using NA electrolyte and Zn||VO2 full batteries also exhibit excellent performance improvements. This work emphasizes the role of variation in the form of additives (especially weak acid-based additives) in fine-tuning the solvation structure and the anode/electrolyte interface, hopefully enhancing the performance of various aqueous metal batteries.

Insights Into Electrolyte Strategies for Suppressing Side Reactions Towards Aqueous Zinc‐Ion Batteries

AbstractAqueous zinc‐ion batteries (AZIBs) have gained significant attention as a promising technology for grid scale energy storage due to their high safety and low cost. Nevertheless, side reactions on the zinc anodes result in a decrease in effi‐ciency decay and capacity loss, hindering the wide‐spread application of AZIBs. Recently, great efforts have been con‐ducted to tackle these challenges, such as modifying the inter‐nal structure of zinc anodes, coating protection on the surface of zinc anodes, and optimizing the electrolytes. However, there is a lack of systematic summary on the design of side reac‐tions‐suppressed zinc anodes, especially through the optimi‐zation strategies of aqueous electrolytes. Herein, this review systematically summarizes the main mechanisms and influence factors of side reactions. Subsequently, we present the main modification strategies based on electrolyte engineering for alleviating side reactions, with a particular emphasis on poly‐mer electrolytes. Lastly, we shed light on the potential research directions and perspectives of aqueous electrolytes, which may promote the development of AZIBs.

A “two cooking with one fish” strategy for modulating both polyaniline cathode and zinc anode towards enhanced kinetics and cycling stability for aqueous zinc ion batteries

The adverse stability of both polyaniline (PANI) and Zn anode remains a challenge to the long−term cyclability and rate capability of aqueous Zn−PANI batteries. Herein, a “two–cooking with one fish” strategy is presented to modulate both PANI cathode and Zn anode, in which nanoscale graphene sheets in cathode can promote ordered growth of PANI array, being conducive to provide large electrochemical active area and efficient transport pathways and alleviate volume variation during repeated charging/discharging process. Meanwhile, the honeycomb–like structure of graphene sheets as protective layer can accelerate zinc ion transport kinetics and suppress side reactions and zinc dendrite growth. Consequently, the optimized G/Zn symmetric cell delivers a remarkable lifespan over 1000 h at 1 mA cm−2 with 1 mAh cm−2. Furthermore, the assembled PANI/G/CC||G/Zn battery could deliver a specific capacity of 265.8 mAh g−1 at 0.2 A g−1, excellent rate capability (145.5 mAh g−1 at 20 A g−1), a maximum energy density of 246.9 W h kg−1 and power density of 8675.9 W kg−1, and especially capacity retention of 91.1 % after 10000 cycles. Combining with additional merits of low cost, eco–friendliness, and safe operation, our design will shed light on resolving the issues on cyclability and rate capability of aqueous Zn−PANI batteries.

Polyoxometalate solution passivation enabling dendrite-free and high-performance zinc anodes in aqueous zinc-ion batteries

Zinc metal anodes in aqueous electrolytes commonly face challenges such as dendrite growth and undesirable side reactions, limiting their application in the field of aqueous zinc-ion batteries (AZIBs) for energy storage. Drawing inspiration from industrial practices involving molybdenum salt solutions for metal modification, a polyoxometalate solution was formulated as a passivation solution for zinc anodes (referred to as MO solution). The formed passivation layer, referred to as the MO layer, exhibited a uniform and protective nature with a thickness of approximately 10 μm. The experimental results demonstrated that this passivation layer effectively suppressed side reactions at the zinc anode interface, as evidenced by lower corrosion current density for MO-Zn anodes. Additionally, the newly plated Zn was uniformly deposited atop the MO layer, ensuring coating integrity and inhibiting dendrite growth. As a result, under more demanding conditions such as a larger current of 8 mA cm−2, the MO-Zn anode displayed an extended cycle life exceeding 420 h in a symmetric battery, with an overpotential as low as 98 mV. This performance significantly outperformed that of commercially available pure Zn foils (with a cycle life of 60 h and an overpotential of 192 mV). Notably, a self-made Na-doped V2O5 served as the cathode (referred to as NaVO), forming the MO-Zn//NaVO full battery. Even under high current test conditions of 2 A/g, the specific capacity of the MO-Zn//NaVO full battery remained substantial at 152.83 mAh/g after 1000 cycles. Furthermore, pouch batteries assembled with NaVO//MO-Zn successfully illuminated small bulbs. This study offers a viable optimization strategy for AZIB anodes and demonstrates the potential of using polyoxometalate solution for etching zinc anodes to inhibit dendrite growth and interfacial corrosion of zinc metal anodes.

Spontaneous anode-molecule interface triggers highly reversible zinc anode

Uncontrolled dendrite growth and side reactions pose obstacles to the practical implementation of aqueous zinc-ion batteries (AZIBs). Here, a cost-effective trace additive, benzohydroxamic acid (BHA), is introduced into a 2.0 M ZnSO4 electrolyte to form a spontaneous anode-molecule interface. Notably, the BHA molecule has strong interactions with Zn2+ ions and can absorb on the anode surface, promoting dynamic transmission and deposition and displaying a role in suppressing side reactions. The impressive cycling stability of the Zn||Zn symmetric cell exceeds 1,400 h at 5.0 mA cm−2 and 5.0 mAh cm−2, achieved by incorporating a trace BHA additive. Furthermore, it endures over 600 h, even at a relatively high depth of discharge (DOD) of 62.6 %. Additionally, under practical conditions (N/P = 3.83), the assembled Zn||I2/AC full cell with BHA additives displays stable cycling for 800 cycles at 2.0 A g−1. This innovative strategy provides a cost-effective approach for achieving AZIBs with an extended lifespan.

Multifunctional Dual‐Metal‐Salt Derived Ternary Eutectic Electrolyte for Highly Reversible Zinc Ion Battery

AbstractDeep eutectic electrolytes offer opportunities for tailoring solvation structure and interface chemistry in advanced batteries, but developing deep eutectic electrolytes for high‐performance zinc ion batteries (ZIBs) remains a challenge. Herein, multifunctional dual‐metal‐salt derived ternary eutectic electrolytes (DMEEs) are designed via a supporting salt strategy for dendrite‐free and long‐lifespan ZIBs. DMEEs are constructed by zinc trifluoromethanesulfonate (Zn(OTF)2), supporting salt of lithium bis(trifluoromethanesulfonyl)imide, and neutral ligand of N‐methylacetamide. Noticeably, supporting salt with weak lattice energy not only induces the reconstruction of intermolecular interactions to form ion pairs and ion aggregates but also tailors the Zn2+ solvation structure and solid electrolyte interface (SEI). The developed DMEEs possess a dual‐anion‐rich Zn2+ solvation shell and induce an inorganic‐rich hybrid SEI, which effectively suppresses side reactions and obtains a dendrite‐free Zn anode with high reversibility. Remarkably, Zn//Zn cells demonstrate cycling stability for over 3000 h, and Zn//PANI full cells deliver no significant capacity decay after 5000 cycles at a high current density of 5 A g−1. This work opens a new avenue to design advanced deep eutectic electrolytes, and the deep understanding of solvation structure and SEI offers guidelines for developing high‐performance batteries.

LiTaO3 mixing effects to suppress side reactions at the LiNi0.8Co0.1Mn0.1O2 cathode and Li5.3PS4.3Cl1.7 solid electrolyte of all-solid-state lithium batteries

Suppressing the side reactions at the solid electrolyte-electrode interface in all-solid-state battery (ASSB) is very important aspect of improving battery performance. Coating an electrochemically stable material on the surface of cathode has been used to suppress the side reactions occurring at interface between solid electrolyte and cathode. However, to achieve effective suppression, the thickness of the coating film must be thin and uniform. Moreover, an expensive ethoxide series typically must be used as a starting material. In this study, LiTaO3 coating material was simply mixed with the solid electrolyte to measure the effect of suppressing side reactions. To synthesize the solid electrolyte Li5.3PS4.3Cl1.7 and the mixing material LiTaO3, high-energy ball milling and wet milling methods were used, respectively. The structural characteristics of the prepared solid electrolytes were studied by powder X-ray diffraction. The LiTaO3 mixed solid electrolyte based ASSB showed a high discharge capacity of 177.3 mAh/g in the initial cycle, whereas the bare solid electrolyte (Li5.3PS4.3Cl1.7) based ASSB showed a discharge capacity of 159.1 mAh/g. To understand the side reactions, electrochemical impedance spectroscopy (EIS) analysis was performed after galvanostatic charge-discharge cycles. The EIS analysis confirmed that the side reaction between a solid electrolyte and a cathode was effectively suppressed in LiTaO3 mixed solid electrolyte based ASSBs.

Lean-water hydrogel electrolyte with improved ion conductivity for dendrite-free zinc-Ion batteries

Although rechargeable aqueous zinc-ion batteries (ZIBs) are regarded as promising energy storage devices, the uncontrollable Zn dendrite and undesirable side reactions severely limit their practical applications. Herein, an anionic hydrogel electrolyte PAM/SA with 3D porous structures is developed by integrating sodium alginate (SA) and polyacrylamide (PAM) networks for highly reversible Zn plating/stripping. Mechanically enhanced and lean-water PAM/SA hydrogel with anionic chains for constructing ionic channels and molecular lubrication films, which facilitate Zn2+ migration for a high ionic conductivity (5.4 S m−1) and Zn2+ transference number (0.86) even under lean-water conditions (about 60%). Based on the experimental and theoretical analysis, the SA chain with strong coordination ability endows PAM/SA with improved desolvation kinetics and the ability to regulate the electric field intensity at the electrode/electrolyte interface, which is beneficial for suppressing side reactions and facilitating directional Zn deposition. Subsequently, the symmetric Zn//Zn cell based on PAM/SA hydrogel electrolyte delivers stable cycles for over 1800 h. The assembled Zn//V2O5 battery based on PAM/SA reveals a high specific capacity and a long cycle life. This work provides a new insight for developing hydrogel electrolytes with high ionic conductivity and lean-water properties toward stable Zn anode

Co-regulation effect of solvation and interface of pyridine derivative enabling highly reversible zinc anode

The poor reversibility and stability of Zn anodes greatly restrict the practical application of aqueous Zn-ion batteries (AZIBs), resulting from the uncontrollable dendrite growth and H2O-induced side reactions during cycling. Electrolyte additive modification is considered one of the most effective and simplest methods for solving the aforementioned problems. Herein, the pyridine derivatives (PD) including 2,4-dihydroxypyridine (2,4-DHP), 2,3-dihydroxypyridine (2,3-DHP), and 2-hydroxypyrdine (2-DHP), were employed as novel electrolyte additives in ZnSO4 electrolyte. Both density functional theory calculation and experimental findings demonstrated that the incorporation of PD additives into the electrolyte effectively modulates the solvation structure of hydrated Zn ions, thereby suppressing side reactions in AZIBs. Additionally, the adsorption of PD molecules on the zinc anode surface contributed to uniform Zn deposition and dendrite growth inhibition. Consequently, a 2,4-DHP-modified Zn/Zn symmetrical cell achieved an extremely long cyclic stability up to 5650 h at 1 mA cm–2. Furthermore, the Zn/NH4V4O10 full cell with 2,4-DHP-containing electrolyte exhibited an outstanding initial capacity of 204 mAh g–1, with a notable capacity retention of 79 % after 1000 cycles at 5 A g–1. Hence, this study expands the selection of electrolyte additives for AZIBs, and the working mechanism of PD additives provides new insights for electrolyte modification enabling highly reversible zinc anode.

Concerted Effect of Ion- and Electron-Conductive Additives on the Electrochemical and Thermal Performances of the LiNi0.8Co0.1Mn0.1O2 Cathode Material Synthesized by a Taylor-Flow Reactor for Lithium-Ion Batteries.

To address the issue that a single coating agent cannot simultaneously enhance Li+-ion transport and electronic conductivity of Ni-rich cathode materials with surface modification, in the present study, we first successfully synthesized a LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material by a Taylor-flow reactor followed by surface coating with Li-BTJ and dispersion of vapor-grown carbon fibers treated with polydopamine (PDA-VGCF) filler in the composite slurry. The Li-BTJ hybrid oligomer coating can suppress side reactions and enhance ionic conductivity, and the PDA-VGCFs filler can increase electronic conductivity. As a result of the synergistic effect of the dual conducting agents, the cells based on the modified NCM811 electrodes deliver superior cycling stability and rate capability, as compared to the bare NCM811 electrode. The CR2032 coin-type cells with the NCM811@Li-BTJ + PDA-VGCF electrode retain a discharge specific capacity of ∼92.2% at 1C after 200 cycles between 2.8 and 4.3 V (vs Li/Li+), while bare NCM811 retains only 84.0%. Moreover, the NCM811@Li-BTJ + PDA-VGCF electrode-based cells reduced the total heat (Qt) by ca. 7.0% at 35 °C over the bare electrode. Remarkably, the Li-BTJ hybrid oligomer coating on the surface of the NCM811 active particles acts as an artificial cathode electrolyte interphase (ACEI) layer, mitigating irreversible surface phase transformation of the layered NCM811 cathode and facilitating Li+ ion transport. Meanwhile, the fiber-shaped PDA-VGCF filler significantly reduced microcrack propagation during cycling and promoted the electronic conductance of the NCM811-based electrode. Generally, enlightened with the current experimental findings, the concerted ion and electron conductive agents significantly enhanced the Ni-rich cathode-based cell performance, which is a promising strategy to apply to other Ni-rich cathode materials for lithium-ion batteries.

Achieving Dendrite-Free Zinc Metal Anodes via Molecule Anchoring and lon-Transport pumping.

The potential for scale-up application has been acknowledged by researchers for rechargeable aqueous zinc-ion batteries (ZIBs). Nonetheless, the progress of the development is significantly impeded due to the instability of the interface between the zinc anode and electrolyte. Herein, efficient and environmentally benign valine (Val) were introduced as aqueous electrolyte additive to stabilize the electrode/electrolyte interface (EEI) via functional groups in additive molecules, thus achieving reversible dendrite-free zinc anode. The amino groups present in Val molecules have a strong ability to adsorb on the surface of zinc metal, enabling the construction of anchored molecular layer on the surface of zinc anodes. The strongly polar carboxyl groups in Val molecules can act as ion-transport pumps to capture zinc ions in the electric double layer (EDL) through coordination chemistry. Therefore, this reconstructed EEI could modulate the zinc ion flux and simultaneously suppress side reactions and dendritic growth of Zn. Consequently, a long stable cycling up to 1400 h at a high current density of 20 mA cm-2 is achieved. Additionally, Zn//V2O5 full cell with Val additive exhibit enhanced cyclability, retaining 77 % capacity after 3000 cycles, displaying significant potential in promoting the commercialization of ZIBs.

Dendrite‐Free Zinc Anode via Oriented Plating with Alkaline Earth Metal Ion Additives

AbstractThe cost‐effectiveness and environmentally friendly nature of aqueous zinc‐ion batteries (ZIBs) have garnered significant attention. Nevertheless, obstacles such as dendrite growth and side reactions have hindered their practical application. Here, an alkaline earth metal ion, strontium ions (Sr2+), is chosen as a dual‐functional electrolyte additive to improve the reversibility of ZIBs. Importantly, Sr2+ ions adsorb on the anode surface, creating a dynamic electrostatic shield layer, thus regulating the Zn2+ deposition behavior and suppressing side reactions. Meanwhile, Sr2+ ions prefer to adsorb on (002) and (110) planes of Zn, thus inducing the preferential deposition of (100) crystal plane and achieving dendrite‐free zinc anode. Consequently, the assembled Zn||Zn symmetric battery delivers an ultralong lifespan of 3500 h, and the Zn||Ti asymmetric battery shows a superior Coulombic efficiency of 99.8% for Zn stripping/plating at 2 mA cm−2. Further, the Zn||NH4V4O10 battery presents an excellent retention of 97.7% over 800 cycles under 2 A g−1. This research introduces a novel alkaline earth metal ion electrolyte additive and establishes its persistent dynamic electrostatic shielding effect and preferentially oriented (100) plane plating, ensuring dendrite‐free zinc deposition. These findings chart a course for further exploration of unexplored alkaline earth elements in enhancing metal battery technologies.

Self-mixing anti-corrosive Zn-In powder composite anode with ultra-long lifespan for aqueous zinc-ion battery

Appropriate design of electrode structure and chemistry for Zn metal anode is important to the kinetics and electrochemical stability of Zn in aqueous batteries. Herein, In modified Zn powder electrode with carbon nanofibers as the stable electric conductive matrix provides an effective approach to simultaneously enhance reaction kinetics and inhibit H2 generation reactions. The designed Zn–In powder electrode presents self-mixing In distribution within the electrode during cycling thus enabling superior anti-corrasion and stable conductive network that significantly alters the Zn deposition behavior. Instant 3D Zn deposition with super-fast interfacial kinetics is achieved due to favorable Zn nucleation and growth as well as suppressed side reactions. Stable cycling of over 6300 h is achieved, which is 30-fold longer lifespan than Zn foil anode. Even at 5 mA cm−2, 5 mAh cm−2 (depth of discharge: 31.1%), Zn–In powder anode still presents stable cycling of over 500 h and low polarization voltage. Ultra-long cycle life of over 20,000 cycles can be achieved for full cells using Zn–In powder electrode paired with V2O5 cathode. Modified composite Zn powder electrode provides an effective and practical approach to address the electrochemical stability of Zn-based anodes in rechargeable cells.

Hybrid Interface Chemistry Enabling Mixed Conducting via Ultrafast Microwave Polarization Toward Dendrite-Free Zn Anodes.

Zn metal anodes in aqueous electrolytes suffer from interface issues including uncontrolled dendrite growth and undesired side reactions, resulting in their limited application in terms of short circuits and cell failure. Herein, a hybrid interface chemistry strategy is developed through ultrafast microwave polarization at the skin region of bare Zn. Owing to efficient Joule heating directed by abundant local hot spots at electron valleys, the rapid establishment of a dense interfacial layer can be realized within a minute. Stabilized Zn with suppressed side reactions or surface corrosion is therefore achieved due to the interfacial protection. Importantly, hybrid zincophilic sites involving laterally/vertically interconnected Cu-Zn intermetallic compound and Zn2+-conductive oxide species ensure mixed charge conducting (denoted as CuHL@Zn), featuring uniformly distributed electric field and boosted Zn2+ diffusion kinetics. As a consequence, CuHL@Zn in symmetric cells affords lifespans of 2800 and 3200h with ultra-low polarization voltages (≈19 and 56mV) at a plating capacity of 1.0mAhcm-2 for 1 and 5mAcm-2, respectively. The CuHL@Zn||MnO2 full cell further exhibits cycling stability with a capacity retention of over 80% for 500 cycles at 2Ag-1.

Weakly Polar Ether‐Aided Ionic Liquid Electrolyte Enables High‐Performance Sodium Metal Batteries over Wide Temperature Range

AbstractSodium (Na) metal batteries (SMBs) have attracted many attentions because of high specific capacity and low redox potential. However, SMBs encounter several crucial challenges including Na dendrites growth, severe interfacial side reactions and safe issues from liquid organic electrolyte. In this study, a non‐flammable 1,2‐bis (1,1,2,2‐tetrafluoroethoxy) ethane (TFEE) aided ionic liquid (IL) electrolyte (TILE) is reported with sodium bis(trifluoromethylsulfonyl)imide (NaTFSI) salt and N‐methyl‐N‐propylpyrrolidinium bis(fluorosulfonyl)imide ([Py13][FSI]) IL solvent. The IL solvent contains plentiful organic cations and anions, which helps to provide a cationic shielding effect by [Py13]+ cations and regulate the Na+ solvation structure with more FSI− and TFSI− anions. The unique solvation structure of Na+ facilitates a stable inorganic‐rich solid electrolyte interphase (SEI), effectively inhibiting unstable Na deposition and suppressing side reactions between the electrolyte and Na‐metal in SMBs. Therefore, the Na3V2(PO4)3 (NVP)||Na cells with TILE can deliver good rate capability and superior cycling performance with capacity retention of 95.5% and Coulombic efficiency of ≈99.9% after 2000 cycles at 5C rate and 25 °C. The high‐voltage NaNi0.33Fe0.33Mn0.33O2(NFM)||Na cells with TILE can also deliver good cycling performance with capacity retention of 92% after 150 cycles in the voltage range of 2.0–4.1 V at 0.5C rate and 25 °C.

Copper-Assisted (Pseudo-)Halochalcogenation of Arynes.

In this report, we describe the multicomponent coupling reaction between arynes, (pseudo)halides, and an electrophilic chalcogen species. Addition of a copper salt enabled smooth conversion by suppressing side reactions. A variety of different aryne precursors as well as seleno- and thiosulfonates were employed, yielding a broad spectrum of ortho-(pseudo)halogenated chalcogenides. This motif was subjected to different cross-coupling approaches, demonstrating the applicability of these compounds as building blocks for more complex structures.