Anionic Chemistry Modulation Enabled Environmental Self-Charging Aqueous Zinc Batteries: The Case of Carbonate Ions.

Anionic chemistry modulation represents a promising avenue to enhance the electrochemical performance and unlock versatile applications in cutting-edge energy storage devices. Herein, we propose a methodology that involves anionic chemistry of carbonate anions to tailor the electrochemical oxidation-reduction reactions of bismuth (Bi) electrodes, where the conversion energy barrier for Bi (0) to Bi (III) has been significantly reduced, endowing anionic full batteries with enhanced electrochemical kinetics and chemical self-charging property. The elaborately designed batteries with an air-switch demonstrate rapid self-recharging capabilities, recovering over 80% of the electrochemical full charging capacity within a remarkably short timeframe of 1 hour and achieving a cumulative self-charging capacity of 5 Ah g-1. The aqueous self-charging battery strategy induced by carbonate anion, as proposed in this study, holds the potential for extending to various anionic systems, including seawater-based Cl- ion batteries. This work offers a universal framework for advancing next-generation multi-functional power sources.

Manipulating Atomic-Coupling in Dual-Cavity Boride Nanoreactor to Achieve Hierarchical Catalytic Engineering for Sulfur Cathode.

The catalytic process of Li2S formation is considered a key pathway to enhance the kinetics of lithium-sulfur batteries. Due to the system's complexity, the catalytic behavior is uncertain, posing significant challenges for predicting activity. Herein, we report a novel cascaded dual-cavity nanoreactor (NiCo-B) by controlling reaction kinetics, providing an opportunity for achieving hierarchical catalytic behavior. Through experimental and theoretical analysis, the multilevel structure can effectively suppress polysulfides dissolution and accelerate sulfur conversion. Furthermore, we differentiate the adsorption (B-S) and catalytic effect (Co-S) in NiCo-B, avoiding catalyst deactivation caused by excessive adsorption. As a result, the as-prepared battery displays high reversible capacity, even with sulfur loading of 13.2 mg cm-2 (E/S=4 µl mg-1), the areal capacity can reach 18.7 mAh cm-2.

Co/Mon Invigorated Bilateral Kinetics Modulation for Advanced Lithium-Sulfur Batteries.

Sluggish sulfur redox kinetics and Li-dendrite growth are the main bottlenecks for lithium-sulfur (Li-S) batteries. Separator modification serves as a dual-purpose approach to address both of these challenges. In this study, the Co/MoN composite is rationally designed and applied as the modifier to modulate the electrochemical kinetics on both sides of the sulfur cathode and lithium anode. Benefiting from its adsorption-catalysis function, the decorated separators (Co/MoN@PP) not only effectively inhibit polysulfides (LiPSs) shuttle and accelerate their electrochemical conversion but also boost Li+ flux, realizing uniform Li plating/stripping. The accelerated LiPSs conversion kinetics and excellent sulfur redox reversibility triggered by Co/MoN modified separators are evidenced by performance, in-situ Raman detection and theoretical calculations. The batteries with Co/MoN@PP achieve a high initial discharge capacity of 1570 mAh g-1 at 0.2 C with a low decay rate of 0.39%, uniform Li+ transportation at 1 mA cm-2 over 800 h. Moreover, the areal capacity of 4.62 mAh cm-2 is achieved under high mass loadings of 4.92 mg cm-2. This study provides a feasible strategy for the rational utilization of the synergistic effect of composite with multifunctional microdomains to solve the problems of Li anode and S cathode toward long-cycling Li-S batteries.

A General "In Situ Etch-Adsorption-Phosphatization" Strategy for the Fabrication of Metal Phosphides/Hollow Carbon Composite for High Performance Liquid/Flexible Zn-Air Batteries.

Benefiting from the admirable energy density (1086 Wh kg-1 ), overwhelming security, and low environmental impact, rechargeable zinc-air batteries (ZABs) are deemed to be attractive candidates for lithium-ion batteries. The exploration of novel oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) bifunctional catalysts is the key to promoting the development of zinc-air batteries. Transitional metal phosphides (TMPs) especially Fe-based TMPs are deemed to be a rational type of catalyst, however, their catalytic performance still needs to be further improved. Considering Fe (heme) and Cu (copper terminal oxidases) are nature's options for ORR catalysis in many forms of life from bacteria to humans. Herein, a general "in situ etch-adsorption-phosphatization" strategy is designed for the fabrication of hollow FeP/Fe2 P/Cu3 P-N, P codoped carbon (FeP/Cu3 P-NPC) catalyst as the cathode of liquid and flexible ZABs. The liquid ZABs manifest a high peak power density of 158.5 mW cm-2 and outstanding long-term cycling performance (≈1100 cycles at 2 mA cm-2 ). Similarly, the flexible ZABs deliver superior cycling stability of 81 h at 2 mA cm-2 without bending and 26 h with different bending angles.

Zinc-Assisted Cobalt Ditelluride Polyhedra Inducing Lattice Strain to Endow Efficient Adsorption-Catalysis for High-Energy Lithium-Sulfur Batteries.

Developing a conductive catalyst with high catalytic activity is considered to be an effective strategy for improving cathode kinetics of lithium-sulfur batteries, especially at large current density and with lean electrolytes. Lattice-strain engineering has been a strategy to tune the local structure of catalysts and to help understand the structure-activity relationship between strain and catalyst performance. Here, Co0.9 Zn0.1 Te2 @NC is constructed after zinc atoms are uniformly doped into the CoTe2 lattice. The experimental/theoretical results indicate that a change of the coordination environment for the cobalt atom by the lattice strain modulates the d-band center with more electrons occupied in antibonding orbitals, thus balancing the adsorption of polysulfides and the intrinsic catalytic effect, thereby activating the intrinsic activity of the catalyst. Benefiting from the merits, with only 4 wt% dosages of catalyst in the cathode, an initial discharge capacity of 1030 mAh g-1 can be achieved at 1 C and stable cycling performances are achieved for 1500/2500 cycles at 1 C/2 C. Upon sulfur loading of 7.7 mg cm-2 , the areal capacity can reach 12.8 mAh cm-2 . This work provides a guiding methodology for the design of catalytic materials and refinement of adsorption-catalysis strategies for the rational design of cathode in lithium-sulfur batteries.

In Situ Growth of CoS2/ZnS Nanoparticles on Graphene Sheets as an Ultralong Cycling Stability Anode for Potassium Ion Storage.

Metal sulfides are promising anodes for potassium-ion batteries (PIBs) due to their high theoretical capacity and abundant active sites; however, their intrinsic low conductivity and poor cycling stability hampered their practical applications. Given this, the rational design of hybrid structures with high stability and fast charge transfer is a critical approach. Herein, CoS2/ZnS@rGO hybrid nanocomposites were demonstrated with stable cubic phases. The synergistic effect of the obtained bimetallic sulfide nanoparticles and highly conductive 2D rGO nanosheets facilitated excellent long-term cyclability for potassium ion storage. Such hybrid nanocomposites delivered remarkable ultrastable cycling performances in PIBs of 159, 106, and 80 mA h g-1 at 1, 1.5, and 2 A g-1 after 1800, 2100, and 3000 cycles, respectively. Moreover, the full-cell configuration with a perylene tetracarboxylic dianhydride organic cathode (CoS2/ZnS@rGO∥PTCDA) exhibited a better electrochemical performance. Besides, when the CoS2/ZnS@rGO nanocomposites were applied as an anode for sodium-ion batteries, the electrode demonstrated a reversible charge capacity of 259 mA h g-1 after 600 cycles at 2 A g-1. In situ X-ray diffraction and ex situ high-resolution transmission electron microscopy characterizations further confirmed the conversion reactions of CoS2/ZnS during insertion/desertion processes. Our synthesis strategy is also a general route to other bimetallic sulfide hybrid nanocomposites. This strategy opens up a new roadmap for exploring hybrid nanocomposites with feasible phase engineering for achieving excellent electrochemical performances in energy storage applications.

Novel WS2 /Fe0.95 S1.05 Hierarchical Nanosphere as a Highly Efficient Electrocatalyst for Hydrogen Evolution Reaction.

Fe0.95 S1.05 with high reactivity and stability was incorporated into WS2 nanosheets via a one-step solvothermal method for the first time. The resulted hybrid catalyst has much higher catalytic activity than WS2 and Fe0.95 S1.05 alone, and the optimal WS2 /Fe0.95 S1.05 hybrid catalyst was found by adjusting the feed ratio. The addition of Fe0.95 S1.05 was proven to be able to enhance the hydrogen evolution reaction (HER) activity of WS2 , and vice versa. At the same time, it was found that the catalytic effect of the hybrid catalyst was the best when the feed ratio was W : Fe=2 : 1. In other words, we confirmed that there is a synergistic effect between W- and Fe-based sulfide hybrid catalysts, and validated that the reason for the improved HER performance is the strong interaction between the two in the middle sulfur. WS2 /Fe0.95 S1.05 -2 hybrid catalyst leads to enhanced HER activity, which shows a low overpotential of ∼0.172 V at 10 mA cm-2 , low Tafel slope of ∼53.47 mV/decade. This study supplies innovative synthesis of a highly active WS2 /Fe0.95 S1.05 hybrid catalyst for HER.

Controlled synthesis of mesoporous single-crystalline TiO2 nanoparticles for efficient photocatalytic H2 evolution.

Mesoporous single-crystals have emerged as a unique family of functional materials, exhibiting excellent performance in various applications, owing to their well-defined accessible mesoporosity and highly single-crystalline structures. Precise tailoring structures of mesoporous single-crystals at the nanoscale remains an unsolved scientific and technical challenge. Herein, we report a facile and general approach for the synthesis of mesoporous single-crystalline TiO2 nanoparticles (designated as MSC-TNs) with distinctive traits including tunable morphologies, controllable particle sizes, well dispersity, high hydrophilicity, well-defined mesoporosity and single-crystal nature. Specifically, the amount of water employed in the precursor solution was seen to give fine control over the particle sizes and morphologies of MSC-TNs. MSC-TNs with different sizes show excellent photocatalytic activity in production of hydrogen from water. Under the illumination of 300 W Xe lamp, MSC-TNs were shown to provide good photodegradation performance with Rhodamine 6 G, as well as H2 production when loaded 1 wt % Pt. In a CH3OH solution H2 was evolved with a rate of 8.98 mmol h-1 g-1, which is significantly higher than with commercial P25 nanoparticles (4.02 mmol h-1 g-1).