In Situ Formed Robust Solid Electrolyte Interphase with Organic-Inorganic Hybrid Layer for Stable Zn Metal Anode.

Stabilizing the Zn anode/electrolyte interface is critical for advancing aqueous zinc ion storage technologies. Addressing this challenge helps minimize parasitic reactions and controls the formation of Zn dendrites, which is fundamental to achieving highly reversible Zn electrochemistry. In this study, 2% by volume of dimethyl sulfoxide (DMSO) is introduced into the baseline zinc sulfate (ZS) electrolyte, which acts as an efficient regulator to form a robust solid-electrolyte interphase (SEI) on the Zn anode. This innovative approach enables uniform Zn deposition and does not substantially modify the Zn2+ solvation structure. The Zn||Zn symmetric cell exhibits an extended cycle life of nearly one calendar year (>8500 h) at a current density of 0.5 mA cm-2 and an areal capacity of 0.5 mAh cm-2. Impressive full cell performance can be achieved. Specifically, the Zn||VS2 full cell achieves an areal capacity of 1.7 mAh cm-2, with a superior negative-to-positive capacity ratio of 2.5, and an electrolyte-to-capacity ratio of 101.4 µL mAh-1, displaying remarkable stability over 1000 cycles under a high mass loading of 11.0 mg cm-2 without significant degradation. This innovative approach in electrolyte engineering provides a new perspective on in situ SEI design and furthers the understanding of Zn anode stabilization.

Dynamic Regulation of the Interfacial pH for Highly Reversible Aqueous Zinc Ion Batteries.

An electrolyte additive, with convenient operation and remarkable functions, has been regarded as an effective strategy for prolonging the cycle life of aqueous zinc ion batteries. However, it is still difficult to dynamically regulate the unstable Zn interface during long-term cycling. Herein, tricine was introduced as an efficient regulator to achieve a pH-stable and byproduct-free interface. The functional zwitterion of tricine not only inhibits interfacial pH perturbation and parasitic reactions by the trapping effect of an anionic group (-COO-) but also simultaneously creates a uniform electric field by the electrostatic shielding effect of a cationic group (-NH2+). Such synergy accordingly eliminates dendrite formation and creates a chemical equilibrium in the electrolyte, endowing the Zn||Zn cell with long-term Zn plating/stripping for 2060 h at 5 mA cm-2 and 720 h at 10 mA cm-2. As a result, the Zn||VS2 full cell under a high cathodic loading mass (8.6 mg cm-2) exhibits exceptional capacity retention of 93% after 1000 cycles.

Structural Design of Electrocatalyst-Decorated MXenes on Sulfur Spheres for Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) are known to be potential next-generation energy storage devices. Recently, our group reported an LSB cathode made using sulfur spheres that has been spherically templated by MXene nanosheets decorated with CoSe2 nanoparticles, forming a "loose-templating" configuration. It was postulated that the minimal restacking of the outer nanoparticle-decorated MXene layer helps to enable facile ionic transport. However, as the nanosheets do not adhere conformally to the internal sphere's surface, such a configuration can be controversial, thus requiring a more systematic understanding. In this work, we report and quantify for the first time the independent and dependent variables involved in this morphology, allowing us to identify that having smaller nanoparticles resulted in better Li+ ion transport and enhanced electrochemical performances. The optimized cathode structure exhibited an initial specific capacity of 1274 mAh/g and a 0.06% decay rate per cycle at 0.5 C over 1000 cycles in LSBs.

Low-Temperature Resistant Stretchable Micro-Supercapacitor Based on 3D Printed Octet-Truss Design.

Recently, stretchable micro-supercapacitors (MSCs) that can be easily integrated into electronic devices have attracted research and industrial attentions. In this work, three-dimensional (3D) stretchable MSCs with an octet-truss electrode (OTE) design have been demonstrated by a rapid digital light processing (DLP) process. The 3D-printed electrode structure is beneficial for electrode-electrolyte interface formation and consequently increases the number of ions adsorbed on the electrode surface. The designed MSCs can achieve a high capacitance as ≈74.76 mF cm-3 under 1 mA cm-3 at room temperature even under a high mechanical deformation, and can achieve 19.53 mF cm-3 under 0.1 mA cm-3 at a low temperature (-30 °C). Moreover, finite element analysis (FEA) reveals the OTE structure provides 8 times more contact area per unit volume at the electrode-electrolyte interface compared to the traditional interdigital electrode (IDE). This work combines structural design and 3D printing techniques, which provides new insights into highly stretchable MSCs for next-generation electronic devices.

Spherical Templating of CoSe2 Nanoparticle-Decorated MXenes for Lithium-Sulfur Batteries.

Two-dimensional MXenes produce competitive performances when incorporated into lithium-sulfur batteries (LSBs), solving key problems such as the poor electronic conductivity of sulfur and dissolution of its polysulfide intermediates. However, MXene nanosheets are known to easily aggregate and restack during electrode fabrication, filtration, or water removal, limiting their practical applicability. Furthermore, in complex electrocatalytic reactions like the multistep sulfur reduction process in LSBs, MXene alone is insufficient to ensure an optimal reaction pathway. In this work, we demonstrate for the first time a loose templating of sulfur spheres using Ti3C2Tx MXene nanosheets decorated with polymorphic CoSe2 nanoparticles. This work shows that the templating of sulfur spheres using nanoparticle-decorated MXene nanosheets can prevent nanosheet aggregation and exert a strong electrocatalytic effect, thereby enabling improved reaction kinetics and battery performance. The S@MXene-CoSe2 cathode demonstrated a long cycle life of 1000 cycles and a low capacity decay rate of 0.06% per cycle in LSBs.

Facile synthesis of a dual-phase CsPbBr3-CsPb2Br5 single crystal and its photoelectric performance.

The emerging metal-halide perovskites are promising for next generation optoelectronic devices. Recently, all-inorganic halide perovskites have been developed and show significantly improved stability compared with organic-inorganic hybrid halide perovskites. Here, we report a facile method based on the coffee ring effect of solvents to synthesize dual-phase CsPbBr3-CsPb2Br5 single crystal microsheets for the first time. The prepared dual-phase CsPbBr3-CsPb2Br5 single crystal is composed of a tetragonal crystalline phase of CsPb2Br5 and a monoclinic phase of CsPbBr3 according to X-ray diffraction (XRD) patterns. The sharp XRD peaks indicate the high crystallinity of the as-synthesized dual-phase CsPbBr3-CsPb2Br5 microsheets. CsPbBr3 is mainly distributed on the edge of the microsheets based on photoluminescence (PL) mapping images. Besides, a photodetector based on the dual-phase CsPbBr3-CsPb2Br5 microsheets exhibits good performance with a high on/off photocurrent ratio of 300 and a photoresponsivity of 2.68 mA W-1. The rise and decay times of the CsPbBr3-CsPb2Br5 microsheet photodetector are around 25.3 ms and 29.6 ms, respectively. The experimental results indicate that the dual-phase CsPbBr3-CsPb2Br5 microsheet could be a good candidate for the fabrication of high-performance micro photodetectors compatible with practical applications.

Two-Dimensional Hybrid Composites of SnS2 Nanosheets Array Film with Graphene for Enhanced Photoelectric Performance.

Two-dimensional (2D) metal dichalcogenides have attracted considerable attention for use in photoelectric devices due to their unique layer structure and strong light-matter interaction. In this paper, vertically grown SnS2 nanosheets array film was synthesized by a facile chemical bath deposition (CBD). The effects of deposition time and annealing temperature on the quality of SnS2 films was investigated in detail. By optimizing the preparation conditions, the SnS2 array film exhibited efficient photoelectric detection performance under sunlight. Furthermore, in order to improve the performance of the photodetector based on SnS2 nanosheets film, a transparent graphene film was introduced as the hole-transport layer by wet-chemical method directly transferring techniques. Graphene/SnS2 nanosheets array film heterojunction photodetectors exhibit enhanced photoresponsivity. The light on/off ratio of the photodetector based on graphene/SnS2 was 1.53, about 1.4 times higher than that of the pristine SnS2 array films. The improved photoresponse performance suggested that the effective heterojunction between vertical SnS2 nanosheets array film and graphene suppresses the recombination of photogenerated carriers. The results indicate that the graphene/SnS2 heterojunction photodetectors have great potential in photodetection devices.