Publications by authors named "Zhengyu Ju"

Lithium (Li) metal has been recognized as a promising anode to advance the energy density of current Li-based batteries. However, the growth of the solid-electrolyte interphase (SEI) layer and dendritic Li microstructure pose significant challenges for the long-term operation of Li metal batteries (LMBs). Herein, we propose the utilization of a suspension electrolyte with dispersed magnetically responsive nanosheets whose orientation can be manipulated by an external magnetic field during cell operation for realizing in situ regeneration in LMBs.

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As one of the most promising electrochemical energy storage systems, aqueous batteries are attracting great interest due to their advantages of high safety, high sustainability, and low costs when compared with commercial lithium-ion batteries, showing great promise for grid-scale energy storage. This invited tutorial review aims to provide universal design principles to address the critical challenges at the electrode-electrolyte interfaces faced by various multivalent aqueous battery systems. Specifically, deposition regulation, ion flux homogenization, and solvation chemistry modulation are proposed as the key principles to tune the inter-component interactions in aqueous batteries, with corresponding interfacial design strategies and their underlying working mechanisms illustrated.

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Solid inorganics, known for kinetically inhibiting polymer crystallization and enhancing ionic conductivity, have attracted significant attention in solid polymer electrolytes. However, current composite polymer electrolytes (CPEs) are still facing challenges in Li metal batteries, falling short of inhibiting severe dendritic growth and resulting in very limited cycling life. This study introduces GaInSn (Galinstan) liquid metal (LM) as an active liquid alternative to conventional passive solid fillers, aiming at realizing self-healing protection against dendrite problems.

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To investigate and define the concept of perioperative sleep disturbance (PSD) among surgical patients, with the goal of aiding clinical practice and research. Walker and Avant's eight-step approach of concept analysis was applied. A systematic search of English literature was conducted in the following databases: PubMed, Web of Science, and CINAHL, with a time restriction from 2010 to August 2023.

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In pursuit of higher energy density in lithium-ion batteries, silicon (Si) has been recognized as a promising candidate to replace commercial graphite due to its high theoretical capacity. However, the pulverization issue of Si microparticles during lithiation/delithiation results in electrical contact loss and increased side reactions, significantly limiting its practical applications. Herein, we propose to utilize liquid metal (LM) particles as the bridging agent, which assemble conductive MXene (TiCT) sheets via coordination chemistry, forming cage-like structures encapsulating mSi particles as self-healing high-energy anodes.

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Lithium-ion batteries with fast-charging/discharging properties are urgently needed for the mass adoption of electric vehicles. Here, we show that fast charging/discharging, long-term stable and high energy charge-storage properties can be realized in an artificial electrode made from a mixed electronic/ionic conductor material (Fe/LiM, where M = O, F, S, N) enabled by a space charge principle. Particularly, the Fe/LiO electrode is able to be charged/discharged to 126 mAh g in 6 s at a high current density of up to 50 A g, and it also shows stable cycling performance for 30,000 cycles at a current density of 10 A g, with a mass-loading of ~2.

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Rational manipulation and assembly of discrete colloidal particles into architected superstructures have enabled several applications in materials science and nanotechnology. Optical manipulation techniques, typically operated in fluid media, facilitate the precise arrangement of colloidal particles into superstructures by using focused laser beams. However, as the optical energy is turned off, the inherent Brownian motion of the particles in fluid media impedes the retention and reconfiguration of such superstructures.

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All-solid-state lithium batteries (ASSLBs) face critical challenges of low cathode loading and poor rate performances, which handicaps their energy/power densities. The widely-accepted aim of high ionic conductivity and low interfacial resistance seems insufficient to overcome these challenges. Here, it is revealed that an efficient ion percolating network in the cathode exerts a more critical influence on the electrochemical performance of ASSLBs.

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To meet the growing demands in both energy and power densities of lithium ion batteries, electrode structures must be capable of facile electron and ion transport while minimizing the content of electrochemically inactive components. Herein, binder-free LiFePO (LFP) cathodes are fabricated with a multidimensional conductive architecture that allows for fast-charging capability, reaching a specific capacity of 94 mAh g at 4 C. Such multidimensional networks consist of active material particles wrapped by 1D single-walled carbon nanotubes (CNTs) and bound together using 2D MXene (TiCT) nanosheets.

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Polyaniline (PANI), with merits of high electronic conductivity and capacity, is a promising material for zinc (Zn)-ion batteries. However, its redox window in Zn batteries is often limited, mainly due to the oxidative degradation at high potentials-in which imine groups can be attacked by water molecules. Here, we introduce phytic acid, a kind of supermolecule acid radical ion, as a dopant and electrolyte additive.

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Over the past few years, lithium-ion batteries have been extensively adopted in electric transportation. Meanwhile, the energy density of lithium-ion battery packs has been significantly improved, thanks to the development of materials science and packing technology. Despite recent progress in electric vehicle cruise ranges, the increase in battery charging rates remains a pivotal problem in electrodes with commercial-level mass loadings.

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As one of the most compact electrochemical energy storage systems, lithium-ion batteries (LIBs) are playing an indispensable role in the process of vehicle electrification to accelerate the shift to sustainable mobility. Making battery electrodes thicker is a promising strategy for improving the energy density of LIBs which is essential for applications with weight or volume constraints, such as electric-powered transportation; however, their power densities are often significantly restricted due to elongated and tortuous charge traveling distances. Here, we propose an effective methodology that couples bidirectional freeze-casting and compression-induced densification to create densified vertically lamellar electrode architectures for compact energy storage.

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Electronic conduction in solid-polymer electrolytes is generally not desired, which causes leakage of electrons or energy loss, and the electronically conductive domains at electrode-electrolyte interfaces can lead to continuous decomposition of electrolytes and shorting issues. However, it is noticed in this work that in an insulating matrix, the conductive domains at certain aspects could also have positive effects on the electrolyte performance with proper control. This work evaluates the limitation and benefits of electronically conductive domains in a solid-polymer electrolyte system and discusses the approach to improve the electrolyte physicochemical properties with densified local electric field distribution, enhanced bulk dielectric property, and charge transfer.

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As one of the prevailing energy storage systems, lithium-ion batteries (LIBs) have become an essential pillar in electric vehicles (EVs) during the past decade, contributing significantly to a carbon-neutral future. However, the complete transition to electric vehicles requires LIBs with yet higher energy and power densities. Here, we propose an effective methodology via controlled nanosheet self-assembly to prepare low-tortuosity yet high-density and high-toughness thick electrodes.

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The increasing demands of electronic devices and electric transportation necessitate lithium-ion batteries with simultaneous high energy and power capabilities. However, rate capabilities are often limited in high-loading electrodes due to the lengthy and tortuous ion transport paths with their electrochemical behaviors governed by complicated electrode architectures still elusive. Here, we report the electrode-level tortuosity engineering design enabling improved charge storage kinetics in high-energy electrodes.

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Charge transport is a key process that dominates battery performance, and the microstructures of the cathode, anode, and electrolyte play a central role in guiding ion and/or electron transport inside the battery. Rational design of key battery components with varying microstructure along the charge-transport direction to realize optimal local charge-transport dynamics can compensate for reaction polarization, which accelerates electrochemical reaction kinetics. Here, the principles of charge-transport mechanisms and their decisive role in battery performance are presented, followed by a discussion of the correlation between charge-transport regulation and battery microstructure design.

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In this work, the Na-K liquid alloy with a charge selective interfacial layer is developed to achieve an impressively long cycling life with small overpotential on a sodium super-ionic conductor solid-state electrolyte (NASICON SSE). With this unique multi-cation system as the platform, we further propose a unique model that contains a chemical decomposition domain and a kinetic decomposition domain for the interfacial stability model. Based on this model, two charge selection mechanisms are proposed with dynamic chemical kinetic equilibrium and electrochemical kinetics as the manners of control, respectively, and both are validated by the electrochemical measurements with microscopic and spectroscopic characterizations.

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Because it has been demonstrated to be effective toward faster ion diffusion inside the pore space, low-tortuosity porous architecture has become the focus in thick electrode designs, and other possibilities are rarely investigated. To advance current understanding in the structure-affected electrochemistry and to broaden horizons for thick electrode designs, we present a gradient electrode design, where porous channels are vertically aligned with smaller openings on one end and larger openings on the other. With its 3D morphology carefully visualized by Raman mapping, the electrochemical properties between opposite orientations of the gradient electrodes are compared, and faster energy storage kinetics is found in larger openings and more concentrated active material near the separator.

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The ever-growing energy demand of modern society calls for the development of high-loading and high-energy-density batteries, and substantial research efforts are required to optimize electrode microstructures for improved energy storage. Low-tortuosity architecture proves effective in promoting charge transport kinetics in thick electrodes; however, heterogeneous electrochemical mass transport along the depth direction is inevitable, especially at high C-rates. In this work, we create an active material gradient in low-tortuosity electrodes along ion-transport direction to compensate for uneven reaction kinetics and the nonuniform lithiation/delithiation process in thick electrodes.

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A common practice in thick electrode design is to increase porosity to boost charge transport kinetics. However, a high porosity offsets the advantages of thick electrodes in both gravimetric and volumetric energy densities. Here we design a freestanding thick electrode composed of highly densified active material regions connected by continuous electrolyte-buffering voids.

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A thick electrode with high areal capacity is a straightforward approach to maximize the energy density of batteries, but the development of thick electrodes suffers from both fabrication challenges and electron/ion transport limitations. In this work, a low-tortuosity LiFePO (LFP) electrode with ultrahigh loadings of active materials and a highly efficient transport network was constructed by a facile and scalable templated phase inversion method. The instant solidification of polymers during phase inversion enables the fabrication of ultrathick yet robust electrodes.

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Increasing the energy density of lithium-sulfur batteries necessitates the maximization of their areal capacity, calling for thick electrodes with high sulfur loading and content. However, traditional thick electrodes often lead to sluggish ion transfer kinetics as well as decreased electronic conductivity and mechanical stability, leading to their thickness-dependent electrochemical performance. Here, free-standing and low-tortuosity N, O co-doped wood-like carbon frameworks decorated with carbon nanotubes forest (WLC-CNTs) are synthesized and used as host for enabling scalable high-performance Li-sulfur batteries.

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Article Synopsis
  • Thick electrodes can enhance battery energy but struggle with lithium-ion transport due to long diffusion paths.
  • Researchers used a modified ice-templating method to create porous electrodes with adjustable wall thickness and channel width, focusing on how these structural features affect battery performance.
  • Thinner-walled electrodes retained about 70% capacity at higher current densities due to better diffusion, suggesting that optimizing electrode design can improve both energy and power in batteries.
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The ever-growing needs for renewable energy demand the pursuit of batteries with higher energy/power output. A thick electrode design is considered as a promising solution for high-energy batteries due to the minimized inactive material ratio at the device level. Most of the current research focuses on pushing the electrode thickness to a maximum limit; however, very few of them thoroughly analyze the effect of electrode thickness on cell-level energy densities as well as the balance between energy and power density.

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Converting CO and H O into carbon-based fuel by IR light is a tough task. Herein, compared with other single-component photocatalysts, the most efficient IR-light-driven CO reduction is achieved by an element-doped ultrathin metallic photocatalyst-Ni-doped CoS nanosheets (Ni-CoS ). The evolution rate of CH over Ni-CoS is up to 101.

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