Guozhong Cao

Severe side reactions and Zn dendrite growth are two main causes deteriorating the stability of zinc metal anodes. N,N-dimethylpropionamide (DMP) is investigated as an electrolyte additive to suppress side reactions and regulate Zn deposition. Experimental results and theoretical calculations demonstrate that the DMP additive can facilitate solvation structure of hydrated Zn2+ and electrode–electrolyte interface in aqueous ZnSO4 electrolyte. DMP develops strong coordination with Zn2+ through the carbonyl group to reduce the water activity, consequently alleviating the water-associated side reactions. DMP prefers to adsorb on (1 0 0) and (1 0 1) planes rather than (0 0 2), inducing the preferential growth of Zn along the (0 0 2) crystal plane. As a result, the ZnSO4 + 10 % DMP electrolyte enables stable Zn plating/stripping in Zn||Zn symmetric cells with a capacity of 1 mAh cm−2 at 1 mA cm−2 for 4000 h, and offers …

Perovskite solar cells represent a revolutionary class of photovoltaic devices that have gained substantial attention for their exceptional performance and potential to provide an affordable and efficient solution for harnessing solar energy. These cells utilize perovskite-structured materials, typically hybrid organicinorganic lead halide compounds, as the light-absorbing layer. The unique crystalline structure of perovskites enables efficient absorption of sunlight and the generation of charge carriers for electricity production. Perovskite solar cells offer several advantages over traditional silicon-based solar cells, including ease of fabrication, lower manufacturing costs, and the potential for flexible and lightweight applications. Perovskite solar cells have demonstrated rapid advancements in power conversion efficiency (PCE), reaching up to~ 25%(with single active layer), which is comparable to or exceeds those of …

The electrochemical properties of vanadium‐based materials as cathode materials for aqueous zinc ion batteries are still restricted by low conductivity, sluggish reaction kinetics, and poor structural stability. Herein, the [VO6] octahedron, as the basic unit of vanadium‐oxide layer of ammonium vanadates (NH4V4O10, denoted as NVO), is incorporated by F atoms to regulate the coordinated environment of vanadium. Density functional theory (DFT) calculations and experimental results show that both physicochemical and electrochemical properties of NVO are improved by F‐doping. The enhanced electronic conductivity accelerates the electron transfer and the expanded interlayer spacing expedites the diffusion kinetics of zinc ions. As a result, the F‐doped NVO (F‐NVO) electrode shows a high discharge capacity (465 mAh g−1 at 0.1 A g−1), good rate capability (260 mAh g−1 at 5 A g−1), and long‐term cycling …

The development of aqueous rechargeable Zn metal batteries, as one of the most promising large‐scale energy storage technology, is hindered largely by dendrite growth and surface passivation of Zn metal anode, which are deleterious to the battery life and Coulombic efficiency (CE). This report demonstrates that ethylenediamine tetramethylenephosphonic acid can in situ coordinate with Zn (EDTMP‐Zn) along with exposing (002) planes for highly reversible and stable Zn plating/stripping. The zincophilic EDTMP‐Zn layer may serve as ion sieves that homogenize Zn ion flux at the Zn anode surface and consequently induce uniform deposition of Zn. The hydrophobic groups in such functional layer is thought to circumvent the Zn anode surface from corrosion and hydrogen evolution reaction. EDTMP15‐Zn modified Zn anode (EDTMP15‐Zn@Zn) delivers a lifespan exceeding 1400 h at 5 mA cm−2, and 1 mAh cm …

Sodium-ion batteries (SIBs) have been extensively studied owing to the abundance and low-price of Na resources. However, the infeasibility of graphite and silicon electrodes in sodium-ion storage makes it urgent to develop high-performance anode materials. Herein, α-MnSe nanorods derived from δ-MnO2 (δ−α-MnSe) are constructed as anodes for SIBs. It is verified that α-MnSe will be transferred into β-MnSe after the initial Na-ion insertion/extraction, and δ−α-MnSe undergoes typical conversion mechanism using a Mn-ion for charge compensation in the subsequent charge–discharge process. First-principles calculations support that Na-ion migration in defect-free α-MnSe can drive the lattice distortion to phase transition (alpha → beta) in thermodynamics and dynamics. The formed β-MnSe with robust lattice structure and small Na-ion diffusion barrier boosts great structure stability and electrochemical kinetics …

Vanadium oxides, particularly hydrated forms like V2O5·nH2O (VOH), stand out as promising cathode candidates for aqueous zinc ion batteries due to their adjustable layered structure, unique electronic characteristics, and high theoretical capacities. However, challenges such as vanadium dissolution, sluggish Zn2+ diffusion kinetics, and low operating voltage still hinder their direct application. In this study, we present a novel vanadium oxide ([C6H6N(CH3)3]1.08V8O20·0.06H2O, TMPA-VOH), developed by pre-inserting trimethylphenylammonium (TMPA+) cations into VOH. The incorporation of weakly polarized organic cations capitalizes on both ionic pre-intercalation and molecular pre-intercalation effects, resulting in a phase and morphology transition, an expansion of the interlayer distance, extrusion of weakly bonded interlayer water, and a substantial increase in V4+ content. These modifications …

Zinc‐iodine batteries (Zn‐I2) are extremely attractive as the safe and cost‐effective scalable energy storage system in the stationary applications. However, the inefficient redox kinetics and “shuttling effect” of iodine species result in unsatisfactory energy efficiency and short cycle life, hindering their commercialization. In this work, Ni single atoms highly dispersed on carbon fibers is designed and synthesized as iodine anchoring sites and dual catalysts for Zn‐I2 batteries, and successfully inhibit the iodine species shuttling and boost dual reaction kinetics. Theoretical calculations indicate that the reinforced d‐p orbital hybridization and charge interaction between Ni single‐atoms and iodine species effectively enhance the confinement of iodine species. Ni single‐atoms also accelerate the iodine conversion reactions with tailored bonding structure of I─I bonds and reduced energy barrier for the dual conversion of …

Due to the poor reversibility and stability of the zinc anode of aqueous zinc ion batteries, the practical application has been seriously restricted. Herein, a highly stable and reversible Zn metal anode was achieved via a novel functional electrolyte additive (1,2-Ethanedisulfonic acid (EDA)), which can construct a dual protective layer of electrolyte additive barrier and in-situ interface. Different from other functional additives, EDA interacts weakly with Zn2+, but it has strong adsorption energy with zinc anode, preventing water molecules from attacking zinc anode. Importantly, an organic/inorganic SEI layer containing SO32-, ZnS-based compounds was electrochemical in-situ formed, which can induce uniform Zn2+ deposition with a limiting 2D diffusion of Zn2+ (within 15 s). These were evidenced by the density functional theory (DFT) calculation, etching X-ray photoelectron spectroscopy (XPS) technology, etc. As a …