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Alkali (Li/Na/K) metal anodes (AMAs), because of their remarkably high energy density and low redox potential, are considered as the most promising anodes for next-generation high-energy battery systems. Nevertheless, high reactivity and uncontrollable volume change of metal anodes during plating/striping inevitably generate dendritic metal and unstable solid electrolyte interphase, inducing low Coulombic efficiency, inferior cycling stability and even safety issues. Architecture design is emerged as an effective approach to address these fatal issues and plenty of attempts have been conducted so far. Instead of simply summarizing the structure-designing strategies to modify AMAs, the review is dedicated to overviewing and categorizing the strategies of architecture design towards the challenges of AMAs by their fundamental design principles from the perspective of electrochemical reaction. Besides, the similarities and differences of three types of alkali metals, in terms of mechanical and chemical properties, have been systematically discussed. Finally, we overviewed the existing challenges, perspectives on further development direction, and outlook for practical applications for AMAs.

An autocatalytic nanosystem with glucose depletion for triple synergetic cancer starvation therapy, cascade amplified hypoxia-activated chemotherapy and enhanced H2O2-dependent chemodynamic therapy.

The poor penetration of nanocarriers within tumor dense extracellular matrices (ECM) greatly restricts the access of anticancer drugs to the deep tumor cells, resulting in low therapeutic efficacy. Moreover, the high toxicity of the traditional chemotherapeutics inevitably causes undesirable side effects. Herein, taking the advantages of biosafe H

Enabling the rechargeable lithium metal batteries (LMBs) is essential for exceeding the energy density of today's Lithium-ion batteries. However, practical challenges in almost all components of LMBs, of which the most serious issues are formation of Li dendrites and uncontrollable volume expansion of lithium metal anodes, hinder their practical applications. Traditional LMBs’ fabrication techniques have some limitations in controlling the geometry and structure of components, which compromises their performance. 3D printing is an ideal manufacturing technique that can increase the specific energy and power density of devices by precisely controlling their geometry and structure from nanoscale to macroscale without relying on any templates. In this work, we review recent advances of 3D printing in rechargeable LMBs in combination with their fundamental principles and representative printing techniques. Then we discuss the applications at component levels. Finally, we summarize the design rationales and practical challenges of 3D printed rechargeable LMBs and give our insights about future outlook of this emerging field.

Defects engineering is an effective strategy to promote electrocatalytic performance. Herein, cobalt binary chalcogenide hollow spheres (CBC HSs) with sulfur (S) defects were prepared by selenium (...

The development of promising zinc anodes mainly suffers from their low plating/stripping coulombic efficiencies when using aqueous electrolyte, which are mainly associated with the interfacial formation of irreversible by-products. It is urgent to develop technologies that can solve this issue fundamentally. Herein, we report an artificial Sc2O3 protective film to construct a new class of interface for Zn anode. The density functional theory simulation and experimental results have proven that the interfacial side reaction was inhibited via a stratified adsorption effect between this artificial layer and Zn anode. Benefiting from this novel structure, the Sc2O3-coated Zn anode can run for more than 100 cycles without short circuit and exhibit low voltage hysteresis, and the coulombic efficiency increases by 1.2%. Importantly, it shows a good application prospect when matched with two of popular manganese-based and vanadium-based cathodes. The excellent electrochemical performance of the Sc2O3-coated Zn anode highlights the importance of rational design of anode materials and demonstrates a good way for developing high-performance Zn anodes with long lifespan and high efficiency.

Silicon oxycarbide (SiOC) is considered as a potential anode material in lithium-ion batteries because of its high theoretical capacity and good structural stability. Despite many such assets, its ...

Multifunctional mesoporous silica-based nanocarriers able to efficiently encapsulate drugs for stimuli-responsive release and display rapid biodegradation are highly desirable. In this work, we dope disulfide bonds and calcium into silica framework by one step method to obtain a redox and pH dual-responsive biodegradable mesoporous silica nanoparticle (BT-Ca-MSN) as a potential drug carrier for synergistic cancer therapy. TEM and ICP-OES are used to assess the biodegradation behavior of BT-Ca-MSN. The results show that BT-Ca-MSN can significantly biodegrade in a concurrent reductive and acidic environment due to the simultaneous disulfide bonds cleavage and Ca2+ release. In addition, BT-Ca-MSN shows efficient drug loading capacity and significant biodegradation-mediated drug release. Moreover, the in-vitro cytotoxicity indicates that BT-Ca-MSN can not only exhibit significant cancer cell killing effect without obvious toxicity on healthy cells via the way of released Ca2+-mediated apoptosis, but also can combine with its loaded doxorubicin hydrochloride for synergistic cancer therapy. This work demonstrates that BT-Ca-MSN is a promising platform as drug carrier, providing a paradigm to rationally design biodegradable silica-based carriers for highly efficient cancer therapy.

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Ameliorating the interfacial issues of the zinc anode, particularly dendrite growth and electrode corrosion, is imperative for rechargeable zinc metal batteries. Herein, an electrochemical-inert li...

Oxygen-defective Co3O2.64S0.33 (namely CoO0.88S0.11) particulate spheres (PS) were prepared via the solid-state sulfurization of spinel Co3O4 at 300 °C in an Ar atmosphere. The introduction of sulfur (S) atoms was found to enrich the surface oxygen vacancies (Vso) remarkably in the as-derived CoO0.88S0.11 PS relative to pristine Co3O4 and CoS2, thus offering more active sites for catalytic reactions. Theoretical calculations were also performed to justify that the enrichment of Vso is favorable to boost the adsorption of H2O molecules. As a result, these CoO0.88S0.11 PS with exposed (111) facets demonstrated enhanced electrocatalytic performance in H2 evolution reaction (HER) with a low overpotential (OP) of 83 mV to realize a current density of 10 mA cm−2, and a high turnover frequency (TOF) of 1.589 H2 s−1 was obtained in 1 M KOH aqueous electrolyte.

Potassium-ion batteries (PIBs) hold great potential as an alternative to lithium-ion batteries due to the abundant reserves of potassium and similar redox potentials of K+/K and Li+/Li. Unfortunately, PIBs with carbonaceous electrodes present sluggish kinetics, resulting in unsatisfactory cycling stability and poor rate capability. Herein, we demonstrate that the synergistic effects of the enlarged interlayer spacing and enhanced capacitive behavior induced by the co-doping of nitrogen and sulfur atoms into a carbon structure (NSC) can improve its potassium storage capability. Based on the capacitive contribution calculations, electrochemical impedance spectroscopy, the galvanostatic intermittent titration technique, and density functional theory results, the NSC electrode is found to exhibit favorable electronic conductivity, enhanced capacitive adsorption behavior, and fast K+ ion diffusion kinetics. Additionally, a series of ex-situ characterizations demonstrate that NSC exhibits superior structural stability during the (de)potassiation process. As a result, NSC displays a high reversible capacity of 302.8 mAh g−1 at 0.1 A g−1 and a stable capacity of 105.2 mAh g−1 even at 2 A g−1 after 600 cycles. This work may offer new insight into the effects of the heteroatom doping of carbon materials on their potassium storage properties and facilitate their application in PIBs.

Noble metal-free electrocatalysts with high activity are highly desirable for the large-scale application of hydrogen evolution reaction (HER). Mo2C-based nanomaterials have been proved as a promising alternative to noble metal-based electrocatalysts owing to the Pt-resembled d-band density and optimal intermediates-adsorption properties. However, the aggregation and excessive growth of crystals often occur during their high-temperature synthesis procedure, leading to low catalytic utilization. In this study, the ultrafine Mo2C/Mo2N heterostructure with large surface and interface confined in the N-doped carbon nanofibers (N-CNFs) was obtained by a melamine-assisted method. The synergistic effect of Mo2C/Mo2N heterostructure and plenty active sites exposed on the surface of ultrafine nanocrystals improves the electrocatalytic activity. Meanwhile, the N-CNFs ensure fast charge transfer and high structural stability during reactions. Moreover, the in-situ synthesis method strengthens the interfacial coupling interactions between Mo2C/Mo2N heterostructure and N-CNFs, further enhancing the electronic conductivity and electrocatalytic activity. Owing to these advantages, Mo2C/Mo2N@N-CNFs exhibit excellent HER performance with a low overpotential of 75 mV at a current density of 10 mV cm−2 in alkaline solution, superior to the single phased Mo2C counterpart and recently reported Mo2C/Mo2N based catalysts. This study highlights a new effective strategy to design efficient electrocatalysts via integrating heterostructure, nanostructure and carbon modification.

Sodium superionic conductor (NASICON)-type compounds have been regarded as promising cathodes for sodium-ion batteries (SIBs) due to their favorable ionic conductivity and robust structural stability. However, their high cost and relatively low energy density restrict their further practical application, which can be tailored by widening the operating voltages with earth-abundant elements such as Mn. Here, we propose a rational strategy of infusing Mn element in NASICON frameworks with sufficiently mobile sodium ions that enhances the redox voltage and ionic migration activity. The optimized structure of Na3.5Mn0.5V1.5(PO4)3/C is achieved and investigated systematically to be a durable cathode (76.6% capacity retention over 5,000 cycles at 20 C) for SIBs, which exhibits high reversible capacity (113.1 mAh·g−1 at 0.5 C) with relatively low volume change (7.6%). Importantly, its high-areal-loading and temperature-resistant sodium ion storage properties are evaluated, and the full-cell configuration is demonstrated. This work indicates that this Na3.5Mn0.5V1.5(PO4)3/C composite could be a promising cathode candidate for SIBs.

One-dimensional (1D) hybrid nanostructures composed of silver/silver sulfide (Ag/Ag2S) and zinc sulfide (ZnS) were prepared by controllable migration of Ag species from the Ag nanowire (NW) core in...

Peroxidase nanozyme, enabling decomposition of hydrogen peroxide (H

Poor tumor penetration is a major obstacle to nanomedicine for achieving effective anticancer therapy. Tumor microenvironment-induced nanomedicine size shrinkage is a promising strategy to overcome the drug penetration barrier across the dense tumor matrix. Herein, we design a size-shrinkable nanocarrier that uses acid as a means of triggering a change in particle size for co-achievement of efficient tumor accumulation followed by deep tumor penetration and rapid clearance from the body. This nanocarrier is constructed from a pH-sensitive lipid layer shell and an ultrasmall amino-functionalized mesoporous silica nanoparticle core capable of loading drugs. After intravenous injection into mice bearing the 4T1 tumor, the nanocarrier with an initial hydrodynamic size of about 33 nm could effectively accumulate at the tumor site through the enhanced permeability and retention effect. Subsequently, in the acidic tumor microenvironment, the lipid layer comprising 9 alkyl-spiropyran (SP-C9) undergoes a volume shrinkage due to the conversion of hydrophobic SP-C9 to amphiphilic 9 alkyl-merocyanine (MC-C9), thus leading to a significant decrease in the entire particle size (hydrodynamic size ∼17 nm) for enhanced intratumoral penetration. Moreover, we find that this size-shrinkable nanocarrier could be rapidly excreted out of the body based on the ICP analysis, significantly reducing biosafety issues. Benefiting from the effective tumor accumulation and penetration of the nanocarrier, the released doxorubicin shows potent antitumor efficacy. This demonstrates the high potential of the designed nanocarrier in solid tumor treatment.