Xueying Zheng

Bio: Xueying Zheng is an academic researcher from Tongji University. The author has contributed to research in topics: Electrolyte & Anode. The author has an hindex of 11, co-authored 26 publications receiving 517 citations. Previous affiliations of Xueying Zheng include Hohai University & Soochow University (Suzhou).

Toward a Stable Sodium Metal Anode in Carbonate Electrolyte: A Compact, Inorganic Alloy Interface

Abstract: Development of the next-generation, high-energy-density, low-cost batteries will likely be fueled by sodium (Na) metal batteries because of their high capacity and the abundance of Na. However, their practical application is significantly plagued by the hyper-reactivity of Na metal, unstable solid electrolyte interphase (SEI), and dendritic Na growth, leading to continuous electrolyte decomposition, low Coulombic efficiency, large impedance, and safety concerns. Herein, we add a small amount of SnCl2 additive in a common carbonate electrolyte so that the spontaneous reaction between SnCl2 and Na metal enables in situ formation of a Na–Sn alloy layer and a compact NaCl-rich SEI. Benefitting from this design, rapid interfacial ion transfer is realized and direct exposure of Na metal to the electrolyte is prohibited, which jointly achieve a nondendritic deposition morphology and a markedly reduced voltage hysteresis in a Na/Na symmetric cell for over 500 h. The Na/SnCl2-added electrolyte/Na3V2(PO4)3 full cel...

Highly Adhesive Li-BN Nanosheet Composite Anode with Excellent Interfacial Compatibility for Solid-State Li Metal Batteries.

Abstract: Solid-state lithium metal batteries (SSLMBs) are promising energy storage devices by employing lithium metal anodes and solid-state electrolytes (SSEs) to offer high energy density and high safety. However, their efficiency is limited by Li metal/SSE interface barriers, including insufficient contact area and chemical/electrochemical incompatibility. Herein, a strategy to effectively improve the adhesiveness of Li metal to garnet-type SSE is proposed by adding only a few two-dimensional boron nitride nanosheets (BNNS) (5 wt %) into Li metal by triggering the transition from point contact to complete adhesion between Li metal and ceramic SSE. The interface between the Li-BNNS composite anode and the garnet exhibits a low interfacial resistance of 9 Ω cm2, which is significantly lower than that of bare Li/garnet interface (560 Ω cm2). Furthermore, the enhanced contact and the additional BNNS in the interface act synergistically to offer a high critical current density of 1.5 mA/cm2 and a stable electrochemical plating/striping over 380 h. Moreover, the full cell paired with the Li-BNNS composite anode and the LiFePO4 cathode shows stable cycling performance at room temperature. Our results introduce an appealing composite strategy with two-dimensional materials to overcome the interface challenges, which provide more opportunities for the development of SSLMBs.

Electrolyte Design Enabling a High-Safety and High-Performance Si Anode with a Tailored Electrode-Electrolyte Interphase.

Abstract: Silicon (Si) anodes are advantageous for application in lithium-ion batteries in terms of their high theoretical capacity (4200 mAh g-1 ), appropriate operating voltage (<0.4 V vs Li/Li+ ), and earth-abundancy. Nevertheless, a large volume change of Si particles emerges with cycling, triggering unceasing breakage/re-formation of the solid-electrolyte interphase (SEI) and thereby the fast capacity degradation in traditional carbonate-based electrolytes. Herein, it is demonstrated that superior cyclability of Si anode is achievable using a nonflammable ether-based electrolyte with fluoroethylene carbonate and lithium oxalyldifluoroborate dual additives. By forming a high-modulus SEI rich in fluoride (F) and boron (B) species, a high initial Coulombic efficiency of 90.2% is attained in Si/Li cells, accompanied with a low capacity-fading rate of only 0.0615% per cycle (discharge capacity of 2041.9 mAh g-1 after 200 cycles). Full cells pairing the unmodified Si anode with commercial LiFePO4 (≈13.92 mg cm-2 ) and LiNi0.5 Mn0.3 Co0.2 O2 (≈17.9 mg cm-2 ) cathodes further show extended service life to 150 and 60 cycles, respectively, demonstrating the superior cathode-compatibility realized with a thin and F, B-rich cathode electrolyte interface. This work offers an easily scalable approach in developing high-performance Si-based batteries through Si/electrolyte interphase regulation.

Interpenetrated Gel Polymer Binder for High Performance Silicon Anodes in Lithium-Ion Batteries

Abstract: Silicon has attracted ever-increasing attention as a high-capacity anode material in Li-ion batteries owing to its extremely high theoretical capacity. However, practical application of silicon anodes is seriously hindered by its fast capacity fading as a result of huge volume changes during the charge/discharge process. Here, an interpenetrated gel polymer binder for high-performance silicon anodes is created through in-situ crosslinking of water-soluble poly(acrylic acid) (PAA) and polyvinyl alcohol (PVA) precursors. This gel polymer binder with deformable polymer network and strong adhesion on silicon particles can effectively accommodate the large volume change of silicon anodes upon lithiation/delithiation, leading to an excellent cycling stability and high Coulombic efficiency even at high current densities. Moreover, high areal capacity of ∼4.3 mAh/cm2 is achieved based on the silicon anode using the gel PAA–PVA polymer binder with a high mass loading. In view of simplicity in using the water soluble gel polymer binder, it is believed that this novel binder has a great potential to be used for high capacity silicon anodes in next generation Li-ion batteries, as well as for other electrode materials with large volume change during cycling.

Fluorinated hybrid solid-electrolyte-interphase for dendrite-free lithium deposition.

Abstract: Lithium metal anodes have attracted extensive attention owing to their high theoretical specific capacity. However, the notorious reactivity of lithium prevents their practical applications, as evidenced by the undesired lithium dendrite growth and unstable solid electrolyte interphase formation. Here, we develop a facile, cost-effective and one-step approach to create an artificial lithium metal/electrolyte interphase by treating the lithium anode with a tin-containing electrolyte. As a result, an artificial solid electrolyte interphase composed of lithium fluoride, tin, and the tin-lithium alloy is formed, which not only ensures fast lithium-ion diffusion and suppresses lithium dendrite growth but also brings a synergistic effect of storing lithium via a reversible tin-lithium alloy formation and enabling lithium plating underneath it. With such an artificial solid electrolyte interphase, lithium symmetrical cells show outstanding plating/stripping cycles, and the full cell exhibits remarkably better cycling stability and capacity retention as well as capacity utilization at high rates compared to bare lithium. Here the authors report a simple method to create a solid electrolyte interphase that is tightly anchored onto the surface of lithium metal anode. This artificial structure suppresses dead and dendrite Li and stores Li via formation of alloys, enabling impressive battery performance.

Sodium-Ion Batteries Paving the Way for Grid Energy Storage

Abstract: Author(s): Hirsh, Hayley S; Li, Yixuan; Tan, Darren HS; Zhang, Minghao; Zhao, Enyue; Meng, Y Shirley