Jiali Yu

Bio: Jiali Yu is an academic researcher from Shenzhen University. The author has contributed to research in topics: Supercapacitor & Anode. The author has an hindex of 18, co-authored 50 publications receiving 858 citations.

A Conductive and Highly Deformable All-Pseudocapacitive Composite Paper as Supercapacitor Electrode with Improved Areal and Volumetric Capacitance

Abstract: Flexible energy storage electronics have gained increasing attention in recent years, but the simultaneous acquiring of high volumetric and high areal capacities as well as excellent flexibility in order to truly implement wearable and portable electronics in practice remains challenging. Here, a conductive and highly deformable freestanding all-pseudocapacitive paper electrode (Ti3 C2 Tx /MnO2 NWs) is fabricated by solution processing of hybrid inks based on Ti3 C2 Tx MXene and ultralong MnO2 nanowires. The resulting Ti3 C2 Tx /MnO2 NWs hybrid paper manifests a remarkable areal capacitance of up to 205 mF cm-2 and outstanding volumetric capacitance of 1025 F cm-3 . Both the values are highly comparable with, or in most cases much higher than those of previously reported MXene-based flexible electrodes. The excellent energy storage performance is well maintained with a capacitance retention of 98.38% during 10 000 charge-discharge cycles. In addition, the flexible supercapacitor demonstrates excellent flexibility and electrochemical stability during repeated mechanical bendings of up to 120°, suggesting great potentials for the applications in future flexible and portable electronics.

SnS2 Nanosheets Coating on Nanohollow Cubic CoS2 /C for Ultralong Life and High Rate Capability Half/Full Sodium-Ion Batteries.

Abstract: Sodium-ion batteries (SIBs) have attracted tremendous interest and become a worldwide research hotpot owing to their low cost and abundant resources. To obtain suitable anode materials with excellent performance for SIBs, an effective and controllable strategy is presented to fabricate SnS2 nanosheets coating on nanohollow cubic CoS2 /C (CoS2 /C@SnS2 ) composites with a hollow structure using Co-metal-organic frameworks as the starting material. As anodes for SIBs, the CoS2 /C@SnS2 electrode exhibits ultralong cycle life and excellent rate performance, which can maintain a high specific capacity of 400.1 mAh g-1 even after 3500 cycles at a current density of 10 A g-1 . When used in a full-cell, it also shows enhanced sodium storage properties and delivers a high reversible capacity of 567.3 mAh g-1 after 1000 cycles at 1 A g-1 . This strategy can pave a way for preparing various metal sulfides with fascinating structure and excellent performance for the potential application in energy storage area.

Uniform core–shell nanobiscuits of Fe7S8@C for lithium-ion and sodium-ion batteries with excellent performance

Abstract: Iron sulfides, as promising anode materials, have been intensively studied, but still encounter problems due to their limited cycle life caused by huge volume changes. In the present work, a facile method has been presented to prepare Fe2O3 nanobiscuits followed by poly(dopamine) coating. After thermally induced sulfurization, Fe7S8@C nanobiscuits have been successfully obtained, which show high specific capacities, excellent rate capabilities and stable cycling stability as anodes for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). They exhibit high reversible capacities of 547.3 mA h g−1 after 600 cycles and 530.8 mA h g−1 after 1000 cycles at a high current density of 5 A g−1 for LIBs and SIBs, respectively. This outstanding electrochemical performance may be attributed to the stress-buffering effect owing to the biscuit-like nanostructure and conformal surface coating with carbon.

Guidelines and trends for next-generation rechargeable lithium and lithium-ion batteries.

Abstract: Commercial lithium-ion (Li-ion) batteries suffer from low energy density and do not meet the growing demands of the energy storage market. Therefore, building next-generation rechargeable Li and Li-ion batteries with higher energy densities, better safety characteristics, lower cost and longer cycle life is of outmost importance. To achieve smaller and lighter next-generation rechargeable Li and Li-ion batteries that can outperform commercial Li-ion batteries, several new energy storage chemistries are being extensively studied. In this review, we summarize the current trends and provide guidelines towards achieving this goal, by addressing batteries using high-voltage cathodes, metal fluoride electrodes, chalcogen electrodes, Li metal anodes, high-capacity anodes as well as useful electrolyte solutions. We discuss the choice of active materials, practically achievable energy densities and challenges faced by the respective battery systems. Furthermore, strategies to overcome remaining challenges for achieving energy characteristics are addressed in the hope of providing a useful and balanced assessment of current status and perspectives of rechargeable Li and Li-ion batteries.

Nitrogen-Doped Mesoporous Carbon Promoted Chemical Adsorption of Sulfur and Fabrication of High-Areal-Capacity Sulfur Cathode with Exceptional Cycling Stability for Lithium-Sulfur Batteries

Abstract: As one important component of sulfur cathodes, the carbon host plays a key role in the electrochemical performance of lithium-sulfur (Li-S) batteries. In this paper, a mesoporous nitrogen-doped carbon (MPNC)-sulfur nanocomposite is reported as a novel cathode for advanced Li-S batteries. The nitrogen doping in the MPNC material can effectively promote chemical adsorption between sulfur atoms and oxygen functional groups on the carbon, as verifi ed by X-ray absorption near edge structure spectroscopy, and the mechanism by which nitrogen enables the behavior is further revealed by density functional theory calculations. Based on the advantages of the porous structure and nitrogen doping, the MPNC-sulfur cathodes show excellent cycling stability (95% retention within 100 cycles) at a high current density of 0.7 mAh cm −2 with a high sulfur loading (4.2 mg S cm −2 ) and a sulfur content (70 wt%). A high areal capacity (≈3.3 mAh cm −2 ) is demonstrated by using the novel cathode, which is crucial for the practical application of Li-S batteries. It is believed that the important role of nitrogen doping promoted chemical adsorption can be extended for development of other high performance carbon-sulfur composite cathodes for Li-S batteries.

Pseudocapacitive Electrodes Produced By Oxidant-Free Polymerization of Pyrrole Between the Layers of 2D Titanium Carbide (MXene)

Abstract: Heterocyclic pyrrole molecules are in situ aligned and polymerized in the -absence of an oxidant between layers of the 2D Ti3C2Tx (MXene), resulting in high volumetric and gravimetric capacitances with capacitance retention of 92% after 25,000 cycles at a 100 mV s(-1) scan rate.

Superconcentrated Electrolytes for a High-Voltage Lithium-Ion Battery

Abstract: Finding a viable electrolyte for next-generation 5 V-class lithium-ion batteries is of primary importance. A long-standing obstacle has been metal-ion dissolution at high voltages. The LiPF6 salt in conventional electrolytes is chemically unstable, which accelerates transition metal dissolution of the electrode material, yet beneficially suppresses oxidative dissolution of the aluminium current collector; replacing LiPF6 with more stable lithium salts may diminish transition metal dissolution but unfortunately encounters severe aluminium oxidation. Here we report an electrolyte design that can solve this dilemma. By mixing a stable lithium salt LiN(SO2F)2 with dimethyl carbonate solvent at extremely high concentrations, we obtain an unusual liquid showing a three-dimensional network of anions and solvent molecules that coordinate strongly to Li(+) ions. This simple formulation of superconcentrated LiN(SO2F)2/dimethyl carbonate electrolyte inhibits the dissolution of both aluminium and transition metal at around 5 V, and realizes a high-voltage LiNi0.5Mn1.5O4/graphite battery that exhibits excellent cycling durability, high rate capability and enhanced safety.