Publications by authors named "Biwei Xiao"

Lithium dendrite growth has become a significant barrier to realizing high-performance all-solid-state lithium metal batteries. Herein, an effective approach is presented to address this challenge through interphase engineering by using a cross-linked polyamide (negative electrostatic potential) that is chemically anchored to the surface of LiPSCl (positive electrostatic potential). This method improves contact between electrolyte particles and strategically modifies the local electronic structure at the grain boundary.

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Article Synopsis
  • - Sodium-ion batteries (SIBs) show potential for advanced energy storage, but their performance is hampered by unstable cathode-electrolyte interphase (CEI), leading to capacity loss and side reactions.
  • - The study introduces a new high-concentration electrolyte combining a stable sulfolane solvent with a non-solvent, creating a thin and durable CEI that maintains stability during cycling.
  • - This improved electrolyte allows the NaNiMnFeO cathode to retain up to 81.15% of its capacity over 400 cycles, while also enhancing safety due to its nonflammable properties, offering a promising approach for future high-voltage SIB applications.
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  • Sodium superionic conductors are important for improving the energy density and safety of Na-ion batteries, but most are based on single-anion frameworks, which have their pros and cons.
  • This research introduces a new class of amorphous Na-ion conductors using a dual-anion framework (NaO-MCl, where M = Hf, Zr, Ta) that shows remarkable properties like high ionic conductivity, stability, and mechanical strength.
  • All-solid-state Na-ion batteries with the new NaO-HfCl electrolyte and NaMnNiFeO cathode demonstrate excellent performance, maintaining 78% capacity after 700 cycles, suggesting a shift in focus toward more advanced superionic conductor designs.
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Layered P2-type sodium manganese oxide has emerged as a promising cathode candidate for sodium-ion batteries due to its appealing cost-effectiveness and high discharge voltage. However, its practical capacity within the voltage range of 2.0-4.

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Low-cost sodium-ion batteries have demonstrated great prospects in energy storage, among which layered transition metal oxides hold great potential as a cathode material. However, the notorious phase transition in layered cathode materials has greatly hampered their cycle life due to large volume changes upon desodiation/sodiation. In this study, by adopting an O3-type NaNiFeMnO (NFM) with controlled synthesis temperatures, we have revealed that the grain size is closely related to its phase transition behaviors.

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Sodium (Na)-metal batteries (SMBs) are considered one of the most promising candidates for the large-scale energy storage market owing to their high theoretical capacity (1,166 mAh g) and the abundance of Na raw material. However, the limited stability of electrolytes still hindered the application of SMBs. Herein, sulfolane (Sul) and vinylene carbonate (VC) are identified as effective dual additives that can largely stabilize propylene carbonate (PC)-based electrolytes, prevent dendrite growth, and extend the cycle life of SMBs.

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Article Synopsis
  • - Inorganic solid-state electrolytes (SSEs) are crucial for enhancing the performance of high-energy all-solid-state batteries (ASSBs), but traditional preparation methods are too energy-intensive for widespread use.
  • - A new, efficient synthesis method for aluminum-based oxyhalide SSEs is introduced, utilizing an exothermic reaction that allows for cost-effective and scalable production with high ionic conductivities, exceeding 10 S/cm at room temperature for various cations.
  • - The key to achieving high conductivities in these SSEs lies in an amorphous matrix made of oxidized chloroaluminate species, which facilitates smooth ion migration, making these materials promising for practical applications in ASSBs due to their low cost and lightweight nature.*
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LiCoO (LCO) cathode materials have attracted significant attention for its potential to provide higher energy density in current Lithium-ion batteries (LIBs). However, the structure and performance degradation are exacerbated by increasing voltage due to the catastrophic reaction between the applied electrolyte and delithiated LCO. The present study focuses on the construction of physically and chemically robust Mg-integrated cathode-electrolyte interface (MCEI) to address this issue, by incorporating Magnesium bis(trifluoromethanesulfonyl)imide (Mg[TFSI]) as an electrolyte additive.

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Protonation of oxide cathodes triggers surface transition metal dissolution and accelerates the performance degradation of Li-ion batteries. While strategies are developed to improve cathode material surface stability, little is known about the effects of protonation on bulk phase transitions in these cathode materials or their sodium-ion battery counterparts. Here, using NaNiO in electrolytes with different proton-generating levels as model systems, a holistic picture of the effect of incorporated protons is presented.

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ConspectusSulfur-based cathode materials have become a research hot spot as one of the most promising candidates for next-generation, high-energy lithium batteries. However, the insulating nature of elemental sulfur or organosulfides has become the biggest challenge that leads to dramatic degradation and hinders their practical application. The disadvantage is more obvious for all-solid-state battery systems, which require both high electronic and ionic migration at the same sites to realize a complete electrochemical reaction.

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Glassy Na-ion solid-state electrolytes (GNSSEs) are an important group of amorphous SSEs. However, the insufficient ionic conductivity of state-of-the-art GNSSEs at room temperature lessens their promise in the development of all-solid-state Na-ion batteries (ASSNIBs) with high energy density and improved safety. Here we report the discovery of a new sodium superionic glass, 0.

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High energy density and high safety are incompatible with each other in a lithium battery, which challenges today's energy storage and power applications. Ni-rich layered transition metal oxides (NMCs) have been identified as the primary cathode candidate for powering next-generation electric vehicles and have been extensively studied in the last two decades, leading to the fast growth of their market share, including both polycrystalline and single-crystal NMC cathodes. Single-crystal NMCs appear to be superior to polycrystalline NMCs, especially at low Ni content (≤60%).

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As exciting candidates for next-generation energy storage, all-solid-state lithium batteries (ASSLBs) are highly dependent on advanced solid-state electrolytes (SSEs). Here, using cost-effective LaCl and CeCl lattice (UCl -type structure) as the host and further combined with a multiple-cation mixed strategy, we report a series of UCl -type SSEs with high room-temperature ionic conductivities over 10  S cm and good compatibility with high-voltage oxide cathodes. The intrinsic large-size hexagonal one-dimensional channels and highly disordered amorphous phase induced by multi-metal cation species are believed to trigger fast multiple ionic conductions of Li , Na , K , Cu , and Ag .

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Utilizing both cationic and anionic oxygen redox reactions is regarded as an important approach to exploit high-capacity layered cathode materials with earth abundant elements. It has been popular strategies to effectively elevate the oxygen redox activities by Li-doping to introduce unhybridized O 2p orbitals in Na MnO -based chemistries or enabling high covalency transition metals in P2-Na Mn TM O (TM = Fe, Cu, Ni) materials. Here, the effect of Li doping on regulating the oxygen redox activities P2-structured Na Ni Mn O materials is investigated.

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The fast-growing demand for energy storage devices has prompted diverse battery techniques, while the state-of-the-art Li-ion batteries (LIBs) continue to flourish, Na-ion batteries (SIBs) have been identified to be a promising alternative to share the burden with LIBs, particularly for large-scale grid storage applications. Both LIBs and SIBs techniques work based on similar fundamental mechanisms, with a heavy focus on the intercalation chemistry of layered transition metal oxides. However, the differences between Li-ion and Na-ion in terms of their size and Lewis acidity induce many different behaviors when crystallizing or diffusing in layered cathode materials.

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Manganese-rich layered oxide materials hold great potential as low-cost and high-capacity cathodes for Na-ion batteries. However, they usually form a P2 phase and suffer from fast capacity fade. In this work, an O3 phase sodium cathode has been developed out of a Li and Mn-rich layered material by leveraging the creation of transition metal (TM) and oxygen vacancies and the electrochemical exchange of Na and Li.

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Lithium-ion batteries (LIBs) with high-nickel (Ni) content LiNiMnCoO ( + + = 1) (NMC with Ni ≥ 0.6) cathodes operated at high charge voltages have been considered as one of the most promising candidates for addressing the challenge of increasing energy density demand. Conventional LiPF-organocarbonate electrolytes exhibit incompatibility with such cell chemistries under certain testing conditions because of the instability of electrode/electrolyte interphases.

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The pursuit of a high-capacity anode material has been urgently required for commercializing sodium-ion batteries with a high energy density and an improved working safety. In the absence of thermodynamically stable sodium intercalated compounds with graphite, constructing nanostructures with expanded interlayer distances is still the mainstream option for developing high-performance carbonaceous anodes. In this regard, a surface-functionalized and pore-forming strategy through a facile CO thermal etching route was rationally adopted to engineer negligible oxygenated functionalities on commercial carbon for boosting the sodium storage process.

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Li- and Mn-rich layered oxides are among the most promising cathode materials for Li-ion batteries with high theoretical energy density. Its practical application is, however, hampered by the capacity and voltage fade after long cycling. Herein, a finite difference method for near-edge structure (FDMNES) code was combined with in situ X-ray absorption spectroscopy (XAS) and transmission electron microscopy/electron energy loss spectroscopy (TEM/EELS) to investigate the evolution of transition metals (TMs) in fresh and heavily cycled electrodes.

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Tracing the dynamic process of Li-ion transport at the atomic scale has long been attempted in solid state ionics and is essential for battery material engineering. Approaches via phase change, strain, and valence states of redox species have been developed to circumvent the technical challenge of direct imaging Li; however, all are limited by poor spatial resolution and weak correlation with state-of-charge (SOC). An ion-exchange approach is adopted by sodiating the delithiated cathode and probing Na distribution to trace the Li deintercalation, which enables the visualization of heterogeneous Li-ion diffusion down to the atomic level.

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Alloy-based nanostructure anodes have the privilege of alleviating the challenges of large volume expansion and improving the cycling stability and rate performance for high energy lithium- and sodium-ion batteries (LIBs and SIBs). Yet, they face the dilemma of worsening the parasitic reactions at the electrode-electrolyte interface and low packing density for the fabrication of practical electrodes. Here, pomegranate Sb@C yolk-shell microspheres were developed as a high-performance anode for LIBs and SIBs with controlled interfacial properties and enhanced packing density.

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Hard carbon (HC) is the state-of-the-art anode material for sodium-ion batteries due to its excellent overall performance, wide availability, and relatively low cost. Recently, tremendous effort has been invested to elucidate the sodium storage mechanism in HC, and to explore synthetic approaches that can enhance the performance and lower the cost. However, disagreements remain in the field, particularly on the fundamental questions of ion transfer and storage and the ideal HC structure for high performance.

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Carbon coating is a commonly employed technique for improving the conductivity of active materials in lithium ion batteries. The carbon coating process involves pyrolysis of organic substance on lithium iron phosphate particles at elevated temperature to create a highly reducing atmosphere. This may trigger the formation of secondary phases in the active materials.

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A novel two-step surface modification method that includes atomic layer deposition (ALD) of TiO followed by post-annealing treatment on spinel LiNi Mn O (LNMO) cathode material is developed to optimize the performance. The performance improvement can be attributed to the formation of a TiMn O (TMO)-like spinel phase resulting from the reaction of TiO with the surface LNMO. The Ti incorporation into the tetrahedral sites helps to combat the impedance growth that stems from continuous irreversible structural transition.

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The development of active, durable, and low-cost catalysts to replace noble metal-based materials is highly desirable to promote the sluggish oxygen reduction reaction in fuel cells. Herein, nitrogen and fluorine-codoped three-dimensional carbon nanowire aerogels, composed of interconnected carbon nanowires, were synthesized for the first time by a hydrothermal carbonization process. Owing to their porous nanostructures and heteroatom-doping, the as-prepared carbon nanowire aerogels, with optimized composition, present excellent electrocatalytic activity that is comparable to commercial Pt/C.

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