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Electrolytes with high stability against both Li anode and high‐voltage cathode are critical for high‐energy and long‐cycling lithium metal batteries (LMBs). However, the free active solvents in common electrolytes are susceptible to decomposition at both Li anode and high‐voltage cathode. Although recently developed locally high‐concentration electrolytes (LHCEs) have largely restricted active solvents via Li+ coordination, the free molecules are still released upon the desolvation of Li+ at the surface of electrodes, causing continuous decomposition during long‐cycling processes. Here, a molecule competitive solvation electrolyte (MCE) is shown to stabilize high‐voltage LMBs by introducing a well‐designed and newly synthetic bipolar solvent molecule with one ion‐dissociative polar head and the other highly fluorinated nonpolar tail. The bipolar molecules competitively dissociate Li+ via weak coordination interactions, drastically reducing the ratio of active solvents in electrolytes and the detrimental decomposition at electrodes during the desolvation processes. Consequently, the MCE enables a 1.4‐Ah Li metal pouch cell with a stack energy density of 450 Wh kg−1 along with exceptional operation stability over 400 cycles (retention: 81%). Furthermore, the MCE also maintains the stable operation of a 2.5‐Ah Li‐S pouch cell with an excellent energy density of 417 Wh kg−1 for 70 cycles under practical conditions. [ABSTRACT FROM AUTHOR]

Monodisperse gold nanoparticles (AuNPs) are an important guarantee of their scientific value and technical reproducibility in applications. The tartrate has a similar molecule structure and physicochemical properties to citrate, bur is much less reducibility and is usually not favorable for the formation of monodisperse AuNPs. We have prepared monodisperse AuNPs with tartrate (potassium sodium tartrate) as reducing and capping agent. Various parameters affecting the monodisperse properties during the preparation of tartrate‐capped AuNPs were analyzed, such as reversing the order of reactant addition and ripening of seeds, while adjusting the synthesis parameters such as time, temperature, and pH value. The final results show that the addition of a trace amount of silver (Ag) ion into chloroauric acid, the monodispersed tartrate‐capped AuNPs can be obtained with the size range of 9–40 nm. The fabricated gold seeds and grown tartrate‐capped AuNPs have narrow size dispersions (or polydispersity, σ<10 %). The minimum size dispersion of AuNPs with twice growth steps was as low as 5.73 %. So, the weak reducing agent of tartrate is one of good candidates to synthesize the monodispersity of AuNPs. Additionally, tartrate‐capped AuNPs have good stability and can be easily modified and form a large two‐dimensional (2D) monolayer nanostructure film. [ABSTRACT FROM AUTHOR]

To address the toxicity concern of extensively used chlorobenzene (CB) and toluene antisolvents, it is urgent to explore green and more efficient antisolvents. In this work, a general and highly reproducible methodology of employing CsPbI3 nanocrystals (NCs) functionalized green alkanes with ultralow‐polarity (Alkane/NCs) as antisolvents to fabricate high‐quality perovskite films is reported. Compared with the CB processed, the perovskite films with much improved quality and high‐orientation are achieved by the Alkane/NCs approach. NCs in the alkane antisolvents are proven to provide enough heterogeneous nuclei, solving effectively the discontinuous film problem encountered from using pure alkanes. Strikingly, the lattice anchoring effect of NCs accounts for the high‐orientation growth of the perovskite films as revealed directly by cryo‐electron microscopy (cryo‐EM). Moreover, the phase segregation that easily occur in the CB processed perovskite film is successfully suppressed by the Alkane/NCs method. The optimal device conversion efficiency is enhanced from 21.59% to 23.10% from CB to octane (OCT)/NCs. Impressively, the alkane/NCs processed perovskite films and their devices exhibit much improved stability over CB, with the conversion efficiency remaining at 94% of its initial value after 500 h light soaking for OCT/NCs device, while the CB device fails at around 100 h. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium batteries (ASSBs) enabled by solid‐state electrolytes (SEs) including oxide‐based and sulfide‐based electrolytes have gained worldwide attention because of their intrinsic safety and higher energy density over conventional lithium‐ion batteries (LIBs). However, despite the high ionic conductivity of advanced SEs, ASSBs still exhibit high overall internal resistance, the most significant contributor of which can be ascribed to the cathode‐SE interfaces. This review seeks to clarify the critical issues regarding the cathode‐SE interfaces, including fundamental principles and corresponding solutions. First, major issues concerning electro‐chemo‐mechanical instability between cathodes and SEs and their formation mechanisms are discussed. Then, specific problems in oxides and sulfides and various solutions and strategies toward interfacial modifications are highlighted. Efforts toward the characterization and analysis of cathode‐SE interfaces with advanced techniques are also summarized. Finally, perspectives are offered on several problems demanding urgent solutions and the future development of SE applications and ASSBs. [ABSTRACT FROM AUTHOR]

The realization of high‐performance thick S cathodes is a critical step to achieve high energy density lithium–sulfur (Li–S) batteries. However, it normally requires a complicated and time‐consuming fabrication processes to obtain high‐performance S cathodes with high mass loading. On the other hand, thick S cathodes fabricated with high‐speed slurry coating method show poor flexibility, capacity, and cycle life due to unpredictable electrode cracking. Herein, an industrial‐speed cracking‐controlled slurry coating method to generate mosaic‐like cracks in the S cathode is developed, which provides vertical channels to facilitate the rapid diffusion of electrolyte, adequate space to accommodate the volume expansion during cycling, and strain‐releasing structure to achieve high flexibility. With this simple method, thick Mosaic‐S cathodes (9 mAh cm−2) provide outstanding energy density, long cycle life, and outstanding flexibility under dynamic bending. This work paves the way for scalable fabrication of high‐performance S cathodes in the near future. [ABSTRACT FROM AUTHOR]

Gas generation induced by parasitic reactions in lithium‐metal batteries (LMB) has been regarded as one of the fundamental barriers to the reversibility of this battery chemistry, which occurs via the complex interplays among electrolytes, cathode, anode, and the decomposition species that travel across the cell. In this work, a novel in situ differential electrochemical mass spectrometry is constructed to differentiate the speciation and source of each gas product generated either during cycling or during storage in the presence of cathode chemistries of varying structure and nickel contents. It unambiguously excludes the trace moisture in electrolyte as the major source of hydrogen and convincingly identifies the layer‐structured NCM cathode material as the source of instability that releases active oxygen from the lattice at high voltages when NCM experiences H2 → H3 phase transition, which in turn reacts with carbonate solvents, producing both CO2 and proton at the cathode side. Such proton in solvated state travels across the cell and becomes the main source for hydrogen generated at the anode side. Mechanisms are proposed to account for these irreversible reactions, and two electrolyte additives based on phosphate structure are adopted to mitigate the gas generation based on the understanding of the above decomposition chemistries. [ABSTRACT FROM AUTHOR]

Solid polymer electrolyte with good thermal stability and flexibility is an excellent candidate for solid‐state lithium metal batteries, while its low ionic conductivity caused by high crystallinity limits its application at ambient temperature. Here a metal organic framework (zeolitic imidazolate framework‐8, ZIF‐8) composited comb‐like methoxy poly(ethylene glycol) acrylate polymer electrolyte (MCPE) with high ionic conductivity (9.96 × 10−5 S cm−1 at 30 °C) is prepared by an in situ UV polymerization method. The as‐prepared MCPE exhibits improved mechanical property due to the introduction of porous ZIF‐8 nanofillers, which is beneficial to suppress the growth of lithium dendrites. Consequently, the LiFePO4||MCPE||Li cells show a high capacity of 116 mAh g−1 at 30 °C and 0.5 C, and maintain 89.4% of initial capacity after 150 cycles with the average Coulombic efficiency of 99.9%. These results demonstrate that the MCPE shows great potential in solid‐state lithium metal batteries near room temperature. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries (LIBs) have been occupying the dominant position in energy storage devices. Over the past 30 years, silicon (Si)‐based materials are the most promising alternatives for graphite as LIB anodes due to their high theoretical capacities and low operating voltages. Nevertheless, their extensive volume changes in battery operation causes the structural collapse of Si‐based electrodes, as well as severe side reactions. In this review, the preparation methods and structure optimizations of Si‐based materials are highlighted, as well as their applications in half and full cells. Meanwhile, the developments of promising electrolytes, binders and separators that match Si‐based electrodes in half and full cells have made great progress. Pre‐lithiation technology has been introduced to compensate for irreversible Li+ consumption during battery operation, thereby improving the energy densities and lifetime of Si‐based full cells. More importantly, almost all related mechanisms of Si‐based electrodes in half and full cells are summarized in detail. It is expected to provide a comprehensive insight on how to develop high‐performance Si‐based full cells. The work can help us understand what happens during the lithiation process, the primary causes of Si‐based half and full cells failure, and strategies to overcome these challenges. [ABSTRACT FROM AUTHOR]

The large‐scale application of Si‐based anodes is impeded by their fast capacity decay, which is mainly attributed to the huge volume expansion upon cycling. The employment of functional binders is one efficient method to mitigate this issue. In this work, a four‐armed polyacrylic acid (4A‐PAA) homopolymer is explored as a remarkably effective binder for Si‐based anodes. The 4A‐PAA binder is prepared via an atom transfer radical polymerization, followed by ester hydrolysis. Compared to the conventional linear polyacrylic acid (PAA) binder, the 4A‐PAA not only shows enhanced toughness due to its decreased molecular regularity and intramolecular hydrogen bond but also exhibits increased binding strength because of its multidimensional binding structure. As a result, the SiOx/graphite electrode using the 4A‐PAA retains a capacity retention of 89.1% and a capacity of 558.1 mAh g−1 after 200 cycles at 0.16 A g−1, which are superior to the PAA electrode, corresponding to 80.4% and 469.3 mAh g−1, respectively. The improved performance is attributed to the employment of the 4A‐PAA, which mitigates the volume change of the SiOx/graphite anode. This work not only offers a promising binder for Si‐based anodes but also presents a universal solution for other anodes with high volume expansion during cycling. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) are considered promising candidates for the next‐generation energy‐storage systems due to their high theoretical capacity and prevalent abundance of sulfur. Their reversible operation, however, encounters challenges from both the anode, where dendritic and dead Li‐metal form, and the cathode, where polysulfides dissolve and become parasitic shuttles. Both issues arise from the imperfection of interphases between electrolyte and electrode. Herein, a new lithium salt based on an imide anion with fluorination and unsaturation in its structure is reported, whose interphasial chemistries resolve these issues simultaneously. Lithium 1, 1, 2, 2, 3, 3‐hexafluoropropane‐1, 3‐disulfonimide (LiHFDF) forms highly fluorinated interphases at both anode and cathode surfaces, which effectively suppress formation of Li‐dendrites and dissolution/shuttling of polysulfides, and significantly improves the electrochemical reversibility of LSBs. In a broader context, this new Li salt offers a new perspective for diversified beyond Li‐ion chemistries that rely on a Li‐metal anode and active cathode materials. [ABSTRACT FROM AUTHOR]

Abstract: Electrochromism has received increasing attention due to its unique electrochromic feature and the induced applications. This review provides an overview on the recent developments in the synthesis and application of the electrochromic metal oxides in smart windows, display devices, e‐skins, and multifunctional energy storage devices. The main cathodic and anodic electrochromic metal oxides are surveyed here, with the discussion of representative examples in details. The current state‐of‐the‐art research activities of the derived multifunctional electrochromic devices are highlighted, i.e., material systems, components, structures, morphology, the resulting performance, etc. Major challenges and potential solutions are also discussed. Additionally, the future perspective on the development trends in electrochromic metal oxides and the commercialization of relevant devices is also proposed. [ABSTRACT FROM AUTHOR]

The stabilization of black phosphorous quantum dots (BPQDs) for optical application under ambient conditions is highly challenging. Here, a facile approach is presented to substantially stabilize BPQDs by making a uniform BPQDs/polymethyl methacrylate (PMMA) composite nanofiber film via an electrospinning technique. As verified by femtosecond laser Z-scan measurement, the BPQDs/PMMA composite nanofiber film that has been stored for three months exhibits almost the same nonlinear optical properties as the fresh BPQDs. Additionally, the BPQDs/PMMA composite nanofiber film demonstrates broadband nonlinear optical response ranging from the visible bandwidth (400 nm) to the mid-IR bandwidth (at least 1930 nm). By employing the BPQDs/PMMA composite nanofiber film as an optical saturable absorber, an ultrashort pulse with the pulse duration of ≈1.07 ps centered at the wavelength of 1567.6 nm is generated in a mode-locked fiber laser. These results suggest that the BPQDs/PMMA composite nanofiber film can combine the advantage of convenient integration and mitigation of the drawback of the easy oxidation of black phosphorous and pave the way for BP-based practical optoelectronic devices. [ABSTRACT FROM AUTHOR]

A novel lath-shaped CuO microassemble consisting of well-crystalized ultrafine nanocrystals was prepared by an ionothermal method with the assistance of ionic liquids ( ILs, 1-butyl-3-methylimidazolium tetrafluoroborate). As anode material of lithium ion batteries, the ILs-CuO exhibits high specific capacity, durability and good rate performance, superior to bare CuO. At a high current density of 1000 mA•g−1, after 100 cycles, ILs-CuO still retains a discharge capacity of 483.2 mAh•g−1. The improved electrochemical performances could be ascribed to the unique microscale lath-shape CuO assembles composed of ultrafine nanostructure. [ABSTRACT FROM AUTHOR]

Self-healing hydrogels have been studied by many researchers via multiple cross-linking approaches including physical and chemical interactions. It is an interesting project in multifunctional hydrogel exploration that a water soluble polymer matrix is cross-linked by combining the ionic coordination and the multiple hydrogen bonds to fabricate self-healing hydrogels with injectable property. This study introduces a general procedure of preparing the hydrogels (termed gelatin-UPy-Fe) cross-linked by both ionic coordination of Fe3+ and carboxyl group from the gelatin and the quadruple hydrogen bonding interaction from the ureido-pyrimidinone (UPy) dimers. The gelatin-UPy-Fe hydrogels possess an excellent self-healing property. The effects of the ionic coordination of Fe3+ and quadruple hydrogen bonding of UPy on the formation and mechanical behavior of the prepared hydrogels are investigated. In vitro drug release of the gelatin-UPy-Fe hydrogels is also observed, giving an intriguing glimpse into possible biological applications. [ABSTRACT FROM AUTHOR]

The introduction of nanomaterials to hydrogels is an effective way to improve the mechanical properties of hydrogels. Herein, carbon nanodot (C-dot) as a new-found excellent nanomaterial is first added to polyvinyl alcohol (PVA) hydrogel to prepare PVA/C-dot hydrogel by freeze-thaw method. The appropriate size and plenty of surface functional groups make C-dot an ideal nucleating agent for PVA crystallization, which leads to form a denser and more uniform cross-linked network in PVA hydrogel, and in turn enhance the mechanical properties of PVA hydrogel. Compared to pure PVA hydrogel, about a 46.4% increase of tensile strength and 18.5% increase of elongation at break are achieved when the content of C-dot in PVA/C-dot hydrogel is 2 wt%, suggesting that C-dot can effectively improve the mechanical properties of PVA hydrogel. Besides, C-dot can endow PVA hydrogel with some new properties, such as fluorescence and reducibility. Herein, Ag nanoparticles are simply introduced and uniformly dispersed in PVA hydrogels with the help of reducibility of C-dot, which can greatly enhance the antibacterial activity of PVA/C-dot hydrogels, and enlarge their application potential in medical field. [ABSTRACT FROM AUTHOR]

Injectable polymeric hydrogels with self-healing property are extremely appealing in biomedical applications for the reason that they could be transplanted via direct injection, which causes minimal invasion to human body. This work presents a novel injectable hydrogel based on strong interaction of quadruple hydrogen bonding from ureido pyrimidinone (UPy) moieties. A new monomer ureido pyrimidinone-diisocyanate-2-hydroxyethyl-methylene acrylic ester (named UPy-NMA) carrying UPy moiety is synthesized for the first time and copolymerized with acrylamide to prepare hydrogel copolymer (PAU). The hydrogel is prepared by dissolving corresponding copolymer into deionized water under certain conditions. Mechanical property of prepared hydrogel is measured by rheometer and the results show that the developed hydrogel display excellent self-healing ability as well as outstanding injectable property. In addition, adequate pore size of hydrogels from scanning electron microscopy also hints that the fabricated hydrogel can provide an intriguing glimpse for potential applications of tissue engineering. [ABSTRACT FROM AUTHOR]

A new kind of agar-polyacrylamide/graphene oxide (agar-PAM/GO) nanocomposite double network (DN) hydrogels is successfully synthesized using one-pot method. The agar-PAM/GO DN hydrogel consists of first agar network cross-linked via hydrogen bond and second PAM network with GO severing as physically cross-linking agent. The factors that influence the mechanical properties of agar-PAM/GO DN gel is investigated. The DN hydrogel exhibits excellent mechanical properties with fracture strain of 4 600% and fracture strength of 332 kPa. In addition, the DN hydrogel shows a good fatigue resistance and self-healing ability. [ABSTRACT FROM AUTHOR]

Gel polymer electrolytes (GPEs) hold great promise for lithium (Li) metal batteries (LMBs). Nevertheless, a critical challenge lies in reducing the thickness of GPEs while maintaining their mechanical integrity to achieve high‐energy‐density LMBs. Additionally, protecting the Li metal anode via electrolyte engineering in GPEs remains demanding. Herein, an innovative ultrathin (1 µm‐thick) yet robust GPE developed using an in situ curing technique, featuring a nanofibrous, exceptionally strong polyethylene separator is presented. The unique microstructure, interfacial conformability, and ultrahigh mechanical robustness of the ultrathin polyethylene separator are thoroughly verified. Enhanced ionic association within the GPE is achieved due to the strong affinity of electrolyte solvent with the fluorinated polymer network, as confirmed by large‐scale molecular dynamics simulations. The optimized solvation structure with high contact ion pairs and aggregate fractions contributes to forming an anion‐derived inorganic‐rich solid electrolyte interphase (SEI), thereby protecting the lithium anode. Benefiting from the ultrahigh robustness of GPE and the excellent interfacial stability, the Li metal full cell with a high mass loading LiNi0.8Co0.1Mn0.1O2 cathode (≈17.3 mg cm−2) and thin Li foil anode (50 µm) demonstrates 91% capacity retention after 200 cycles. This design demonstrates a feasible approach toward the practical quasi‐solid‐state LMBs. [ABSTRACT FROM AUTHOR]

The developing electric vehicles and portable electronics urgently require rechargeable lithium batteries with high energy density and high safety. Lithium‐sulfur (Li‐S) batteries have shown significant advantages in their high energy density. However, the use of traditional polymer binders faces significant challenges, such as soluble polysulfides, large volume changes, and electrode flammability, resulting in performance degradation and safety hazards. Here, a polymeric aluminophosphate (AP) is for the first time proposed as an inorganic polymer binder to simultaneously realize high energy density, long cycling stability, and reliable safety of Li‐S batteries. Benefiting from the synergistic effect of polar P‐O and Al‐O chain segments, the AP binder provides strong mechanical adhesion, anchors polysulfides, and promotes the redox kinetics of sulfur electrodes. The AP binder also ensures high flame retardancy for sulfur electrodes at an extremely low dosage of 2 wt%. Consequently, the retardant sulfur electrode can be operated stably with high specific capacities (1190 mAh g−1), high capacity retention rates (>99.1%) during 500 cycles, and excellent rate capability (3 C). Based on the entire cell, the soft‐packaged Li‐S full battery provides high capacities (3.6 mAh cm−2), high cell energy density (415 Wh kg−1 and 297 Wh L−1), and high capacity retention rates (>99.8%). [ABSTRACT FROM AUTHOR]

In article number 1702437, Zhouguang Lu, Han Zhang, and co‐workers present a method to stabilize black phosphorus quantum dots (BPQDs). BPQDs/polymethyl methacrylate (PMMA) composite nanofiber film, made via an electrospinning technique, preserves nonlinear optical properties similar to just‐prepared BPQDs even after three months storage. [ABSTRACT FROM AUTHOR]