Wrapping Sb2Te3 with a Graphite Layer toward High Volumetric Energy and Long Cycle Li-Ion Batteries

Rational Design of Multinary Metal Chalcogenide Bi0.4 Sb1.6 Te3 Nanocrystals for Efficient Potassium Storage

Multinary metal chalcogenides hold considerable promise for high-energy potassium storage due to their numerous redox reactions. However, challenges arise from issues such as volume expansion and sluggish kinetics. Here, a design featuring a layered ternary Bi0.4 Sb1.6 Te3 anchored on graphene layers as a composite anode, where Bi atoms act as a lattice softening agent on Sb, is presented. Benefiting from the lattice arrangement in Bi0.4 Sb1.6 Te3 and structure, Bi0.4 Sb1.6 Te3 /graphene exhibits a mitigated expansion of 28% during the potassiation/depotassiation process and demonstrates facile K+ ion transfer kinetics, enabling long-term durability of 500 cycles at various high rates. Operando synchrotron diffraction patterns and spectroscopies including in situ Raman, ex situ adsorption, and X-ray photoelectron reveal multiple conversion and alloying/dealloying reactions for potassium storage at the atomic level. In addition, both theoretical calculations and electrochemical examinations elucidate the K+ migration pathways and indicate a reduction in energy barriers within Bi0.4 Sb1.6 Te3 /graphene, thereby suggesting enhanced diffusion kinetics for K+ . These findings provide insight in the design of durable high-energy multinary tellurides for potassium storage.

Understanding the Configurational Entropy Evolution in Metal-Phosphorus Solid Solution for Highly Reversible Li-Ion Batteries

The high-entropy materials (HEM) have attracted increasing attention in catalysis and energy storage due to their large configurational entropy and multiunique properties. However, it is failed in alloying-type anode due to their Li-inactive transition-metal compositions. Herein, inspired by high-entropy concept, the Li-active elements instead of transition-metal ones are introduced for metal-phosphorus synthesis. Interestingly, a new Zn_x Ge_y Cu_z Si_w P₂ solid solution is successfully synthesized as proof of concept, which is first verified to cubic system in F-43m. More specially, such Zn_x Ge_y Cu_z Si_w P₂ possesses wide-range tunable region from 9911 to 4466, in which the Zn_0.5 Ge_0.5 Cu_0.5 Si_0.5 P₂ accounts for the highest configurational entropy. When served as anode, Zn_x Ge_y Cu_z Si_w P₂ delivers large capacity (>1500 mAh g^-1 ) and suitable plateau (≈0.5 V) for energy storage, breaking the conventional view that HEM is helpless for alloying anode due to its transition-metal compositions. Among them, the Zn_0.5 Ge_0.5 Cu_0.5 Si_0.5 P₂ exhibits the highest initial coulombic efficiency (ICE) (93%), Li-diffusivity (1.11 × 10^-10 ), lowest volume-expansion (34.5%), and best rate performances (551 mAh g^-1 at 6400 mA g^-1 ) owing to its largest configurational entropy. Possible mechanism reveals the high entropy stabilization enables good accommodation of volume change and fast electronic transportation, thus supporting superior cyclability and rate performances. This large configurational entropy strategy in metal-phosphorus solid solution may open new avenues to develop other high-entropy materials for advanced energy storage.

Design, synthesis and application of two-dimensional metal tellurides as high-performance electrode materials

Multifunctional electrode materials with inherent conductivity have attracted extensive attention in recent years. Two-dimensional (2D) metal telluride nanomaterials are more promising owing to their strong metallic properties and unique physical/chemical merits. In this review, recent advancements in the preparation of 2D metal tellurides and their application in electrode materials are presented. First, the most available preparation methods, such as hydro/solvent thermal, chemical vapor deposition, and electrodeposition, are summarized. Then, the unique performance of metal telluride electrodes in capacitors, anode materials of Li/Na ion batteries, electrocatalysis, and lithium-sulfur batteries are discussed. Finally, significant challenges and opportunities in the preparation and application of 2D metal tellurides are proposed.

Recent advances of metal telluride anodes for high-performance lithium/sodium-ion batteries

Metal tellurides (MTs) have emerged as highly promising candidate anode materials for state-of-the-art lithium-ion batteries (LIBs) and sodium ion batteries (SIBs). This is owing to the unique crystal structure, high intrinsic conductivity, and high trap density of such materials. The present work delivers a detailed discussion on the latest research and progress associated with the use of MTs for LIBs/SIBs with a focus on reaction mechanisms, challenges, electrochemical performance, and synthesis strategies. Further, the prospects and future development of MT anode materials are discussed in terms of strategies to overcome the existing limitations. This review provides both an in-depth understanding of MTs and provides the driving force for expanding research on MTs for energy storage and conversion applications.

Binder-Free, Flexible, and Self-Standing Non-Woven Fabric Anodes Based on Graphene/Si Hybrid Fibers for High-Performance Li-Ion Batteries

High-capacity silicon (Si) is recognized as a potential anode material for high-performance lithium-ion batteries (LIBs). Unfortunately, large volume expansion during discharge/charge processes hinders its areal capacity. In this work, we design a flexible graphene-fiber-fabric (GFF)-based three-dimensional conductive network to form a binder-free and self-standing Si anode for high-performance LIBs. The Si particles are strongly wrapped in graphene fibers. The substantial void spaces caused by the wrinkled graphene in fibers enable effective accommodation of the volume change of Si during lithiation/delithiation processes. The GFF/Si-37.5% electrode exhibits an excellent cyclability with a specific capacity of 920 mA h g^-1 at a current density of 0.4 mA cm^-2 after 100 cycles. Furthermore, the GFF/Si-29.1% electrode exhibits an excellent reversible capacity of 580 mA h g^-1 at a current density of 0.4 mA cm^-2 after 400 cycles. The capacity retention of the GFF/Si-29.1% electrode is up to 96.5%. More importantly, the GFF/Si-37.5% electrode with a mass loading of 13.75 mg cm^-2 achieves a high areal capacity of 14.3 mA h cm^-2, which outperforms the reported self-standing Si anode. This work provides opportunities for realizing a binder-free, flexible, and self-standing Si anode for high-energy LIBs.

Carbon nanotubes coupled with layered graphite to support SnTe nanodots as high-rate and ultra-stable lithium-ion battery anodes

SnTe exhibits a layered crystal structure, which enables fast Li-ion diffusion and easy storage, and is considered to be a promising candidate for an advanced anode material. However, its applications are hindered by the large volume variation caused by intercalation/deintercalation during the electrochemical reaction processes. Herein, topological insulator SnTe and carbon nanotubes (CNTs) supported on a graphite (G) carbon framework (SnTe-CNT-G) were prepared as a new, active and robust anode material for high-rate lithium-ion batteries by a scalable ball-milling method. Remarkably, the SnTe-CNT-G composite used as a lithium-ion battery anode offered an excellent reversible capacity of 840 mA h g-1 at 200 mA g-1 after 100 cycles and high initial coulombic efficiencies of 76.0%, and achieved a long-term cycling stability of 669 mA h g-1 at 2 A g-1 after 1400 cycles. The superior electrochemical performance of SnTe-CNT-G is attributed to the stable design of its electrode structure and interesting topological transition of SnTe, combined with multistep conversion and alloying processes. Furthermore, in situ X-ray diffraction and ex situ X-ray photoelectron spectroscopy were employed to study the reaction mechanism. The results presented here provide new insights to design and reveal the reaction mechanisms of transition metal telluride materials in various energy-storage materials.