Realization of a 594 Wh kg−1 Lithium-Metal Battery Using a Lithium-Free V2O5 Cathode with Enhanced Performances by Nanoarchitecturing

To realize a high-energy lithium metal battery (LMB) using a high-capacity Li-free cathode, in this work, nanoplate-stacked V₂O₅ with dominantly exposed (010) facets and a relatively short [010] length is proposed to be used as a cathode. The V₂O₅ nanostructure can be fabricated via a modified hydrothermal method, including a Li⁺ crystallization inhibitor, followed by heat treatment. In particular, the enlargement of the favorable Li⁺ diffusion pathway in the [010] direction and the formation of a robust hierarchical nanoplate-stacked structure in the modified V₂O₅ improves the electrochemical kinetics and stability; as a result, the nanoplate-stacked V₂O₅ electrode exhibits a higher capacity and rate performance (258 mAh g⁻¹ at 50 mA g⁻¹ [0.17 C], 140 mAh g⁻¹ at 1 A g⁻¹ [3.4 C]) and cycling capability (79% capacity retention after 100 cycles at 0.5 C) compared to the previously reported V₂O₅ nanobelt electrode. Notably, the LMB composed of Li//nanoplate-stacked V₂O₅ full-cells shows high specific energy densities of 594.1 and 296.2 Wh kg⁻¹ at 0.1 and 1.0 C, respectively, and a high Coulombic efficiency of 99.6% during 50 cycles.     

Lithium Iron Aluminum Nickelate,LiNixFeyAlzO2—New Sustainable Cathodes for Next-Generation Cobalt-Free Li-Ion Batteries

In recent years, cobalt has become a critical constraint on the supply chain of the Li-ion battery industry. With the ever-increasing projections for electric vehicles, the dependency of current Li-ion batteries on the ever-fluctuating cobalt prices poses serious environmental and sustainability issues. To address these challenges, a new class of cobalt-free materials with general formula of LiNi_xFe_yAl_zO₂ (x + y + z = 1), termed as the lithium iron aluminum nickelate (NFA) class of cathodes, is introduced. These cobalt-free materials are synthesized using the sol–gel process to explore their compositional landscape by varying aluminum and iron. These NFA variants are characterized using electron microscopy, neutron and X-ray diffraction, and Mössbauer and X-ray photoelectron spectroscopy to investigate their morphological, physical, and crystal-structure properties. Operando experiments by X-ray diffraction, Mössbauer spectroscopy, and galvanostatic intermittent titration have been also used to study the crystallographic transitions, electrochemical activity, and Li-ion diffusivity upon lithium removal and uptake in the NFA cathodes. NFA compositions yield specific capacities of ≈200 mAh g⁻¹, demonstrating reasonable rate capability and cycling stability with ≈80% capacity retention after 100 charge/discharge cycles. While this is an early stage of research, the potential that these cathodes could have as viable candidates in next-generation cobalt-free lithium-ion batteries is highlighted here.     

Efficient Lithium/Sodium-Ion Storage by Core–Shell Carbon Nanospheres@TiO2 Decorate by Epitaxial WSe2 Nanosheets Derived from Bimetallic Polydopamine Composites

Metal-polydopamine coordination chemistry attracts great attention owing to the synergistic effect of adjustable components and advantageous structures. However, few efforts have been devoted to exploring bimetal-polydopamine composites, especially for multistructural composites with high-capacity components and high stability. In this regard, the TiO₂@C-WSe₂ core–shell nanospheres are designed and fabricated based on Ti-W-polydopamine composites after selenization, in which the TiO₂ nanoparticles are encapsulated or embedded in the carbon nanospheres and the external WSe₂ nanosheets are grown epitaxially on the carbon surfaces, featuring multiple channels for ion diffusion and abundant active edges for electrochemical reactions. The introduction of WSe₂ not only greatly improves the capacity but also results in exponential growth of the active edge. As a result, the as-prepared TiO₂@C-WSe₂ displayed long-term cycling performance in lithium-ion batteries. Furthermore, the anode is assembled into sodium-ion batteries, manifesting a stable capacity of 352 mA h g⁻¹ at 1.0 A g⁻¹ even after 2000 cycles, one of the best performances for polydopamine-based composites. Enhanced performance can be attributed to the synergies of high-capacity components and different dimensional materials. This work highlights that the rational design of functional structures provides a novel inspiration for electrodes with effective nanoarchitectures.     

Nanosized-bismuth-embedded 1D carbon nanofibers as high-performance anodes for lithium-ion and sodium-ion batteries

Bi is a promising candidate for energy storage materials because of its high volumetric capacity,stability in moisture/air,and facile preparation.In this study,the electrochemical performance of nanosized-Bi-embedded one-dimensional (1D) carbon nanofibers (Bi/C nanofibers) as anodes for Li-ion batteries (LIBs) and Na-ion batteries (NIBs) was systematically investigated.The Bi/C nanofibers were prepared using a single-nozzle electrospinning method with a specified Bi source followed by carbothermal reduction.Abundant Bi nanoparticles with diameters of approximately 20 nm were homogeneously dispersed and embedded in the 1D carbon nanofibers,as confirmed by structural and morphological characterization.Electrochemical measurements indicate that the Bi/C nanofiber anodes could deliver a long cycle life for LIBs and a preferable rate performance for NIBs.The superior electrochemical performances of the Bi/C nanofiber anodes are attributed to the 1D carbon nanofiber structure and uniform distribution of Bi nanoparticles embedded in the carbon matrix.This unique embedded structure provides a favorable electron carrier and buffering matrix for the effective release of mechanical stress caused by volume change and prevents the aggregation of Bi nanoparticles.