A Black Phosphorus-Graphite Composite Anode for Li-/Na-/K-Ion Batteries.

Bismuth selenide holds great promise as a kind of conversion-alloying-type anode material for alkali metal ion storage because of its layered structure with large interlayer spacing and high theoretical specific capacity. Nonetheless, its commercial development has been significantly hammered by the poor kinetics, severe pulverization, and polyselenide shuttle during the charge/discharge process. Herein, Sb-substitution and carbon encapsulation strategies are simultaneously employed to synthesize SbxBi2-xSe3 nanoparticles decorated on Ti3C2Tx MXene with encapsulation of N-doped carbon (SbxBi2-xSe3/MX⊂NC) as anodes for alkali metal ion storage. The superb electrochemical performances could be assigned to the cationic displacement of Sb3+ that effectively inhibits the shuttling effect of soluble polyselenides and the confinement engineering that alleviates the volume change during the sodiation/desodiation process. When used as anodes for sodium- and lithium-ion batteries, the Sb0.4Bi1.6Se3/MX⊂NC composite exhibits superior electrochemical performances. This work offers valuable guidance to suppress the shuttling of polyselenides/polysulfides in high-performance alkali metal ion batteries with conversion/alloying-type transition metal sulfide/selenide anode materials.

Black phosphorus (BP) is a newly discovered two-dimensional material that has promising applications from bioelectronics to biomedicine. However, facile oxidation of BP leads to changes in surface ...

Functionalized few-layer black phosphorus with super-wettability towards enhanced reaction kinetics for rechargeable batteries

Design of Sb2Se3-based nanocomposites for high-performance alkali metal ion batteries driven by a hybrid charge storage mechanism

Since its successful isolation in 2014, two-dimensional black phosphorus (BP) has triggered considerable interest ffrom physicists, chemists and material scientists. Benefitting from the unique structural and physicochemical properties, BP has been explored in various applications including photoelectric, biological and electrochemical fields. Besides, BP also shows great potential as a promising electrode material and electrocatalyst in energy storage and electrocatalytic applications, and tremendous progress has been made in these electrochemical fields in recent years. Here, this review highlights the recent experimental and theoretical progress of BP-based electrodes and electrocatalysts. The latest recent advances of BP-based functional materials in energy storage applications including lithium-, magnesium- and sodium-ion batteries, lithium–sulfur batteries and supercapacitors, are presented in detail. Further, the emerging electrocatalytic applications of BP for hydrogen evolution reaction, oxygen evolution reaction and nitrogen reduction reaction are systematically reviewed with achievements and challenges. Finally, we offer brief personal comments on the existing challenges and prospective outlook on the basis of current research progress.

MoS2 has attracted tremendous attention as a promising electrode material for rechargeable alkali metal ion (Li+ , Na+ , K+ ) batteries due to its high capacity and low cost. However, the practical application of MoS2 for energy storage has not been achieved yet, which is restricted by its intrinsic charge-storage behavior. Debates still exist in this field although great efforts have been made to reveal alkali metal ion (Li+ , Na+ , K+ ) storage mechanism of MoS2 . This Minireview aims to provide an analysis and summary of the related phase conversion, structure collapse, and loss of active material in a MoS2 electrode during the intercalation/extraction process of alkali metal ions. Hence, the fundamental understanding about the charge storage in MoS2 is of importance for the rational design of MoS2 electrodes with excellent electrochemical performance.

Black phosphorus (BP) has shown great potential as a semiconductor material beyond graphene and MoS2 because of its intrinsic band gap and high mobility. Moreover, the biocompatibility of the final biodegradation products of BP has led to extensive research on biomedical applications. Herein, physically transient field-effect transistors (FETs) based on black phosphorus have been demonstrated using peptide insulator as a gate dielectric layer. The fabricated devices show high hole mobility up to 468 cm2 V-1 s-1 and on-off current ratio over 103. The combined use of black phosphorus, peptide, and molybdenum provides rapid disappearance of the devices within 36 h. Dissolution kinetics and cytotoxicity of black phosphorus are assessed to clarify its availability to be applied in transient electronics. This work provides transient FETs with high degradability and high performance based on biocompatible black phosphorus.

The development and optimization of promising anode material for next-generation alkali metal ion batteries are significant for clean energy evolution. 2D MXenes have drawn extensive attention in electrochemical energy storage applications, due to their multiple advantages including excellent conductivity, robust mechanical properties, hydrophilicity of its functional terminations, and outstanding electrochemical storage capability. In this review, the categories, properties, and synthesis methods of MXenes are first outlined. Furthermore, the latest research and progress of MXenes and their composites in alkali metal ion storage are also summarized comprehensively. A special emphasis is placed on MXenes and their hybrids, ranging from material design and fabrication to fundamental understanding of the alkali ion storage mechanisms to battery performance optimization strategies. Lastly, the challenges and personal perspectives of the future research of MXenes and their composites for energy storage are presented.

High-pressure and high-temperature synthesis of black phosphorus-graphite anode material for lithium-ion batteries

The finding of nickel extraction material: How nickel ferrocyanide offer excess capacity

Interlayer engineering of graphite anodes in alkali metal ion (M = Li, Na, and K) batteries is carried out based on the first-principles calculations. By increasing the interlayer spacing of graphite, the specific capacity of Li or Na does not increase while that of K increases continuously (from 279 mA h g-1 at the equilibrium interlayer spacing to 1396 mA h g-1 at the interlayer spacing of 20.0 Å). As the interlayer spacing increases, the electrostatic potential of graphite becomes smoother, and the ability to buffer the electrostatic potential fluctuation becomes poorer in M ions. These two effects jointly lead to minima of the diffusion barrier of M ions on graphite (0.01-0.05 eV), instead of strictly monotonous declines with the increasing interlayer spacing. To perform the interlayer engineering of anode candidates more efficiently, a set of high-throughput programs has been developed and can be easily applied to other systems. Our research has guiding significance for achieving the optimal effect in interlayer engineering experimentally.

Electrochemical energy storage devices commonly face a trade-off between specific energy and power capability. Black phosphorus offers a high theoretical capacity of 2596 mA h g-1, but its practical application is limited by slow reaction kinetics during multiphase phosphorus redox processes. These sluggish transformations, involving bond rearrangement and soluble intermediates, hinder fast charging and compromise cycling stability. Here we show that introducing phosphorus-nitrogen bonds into a black phosphorus/carbon composite regulates the reaction pathway and accelerates charge transport. The engineered bonding environment modifies the electronic structure of black phosphorus and lowers lithium-ion diffusion barriers, enabling faster lithiation and delithiation. Meanwhile, nitrogen sites in the carbon matrix confine lithium-phosphorus intermediates, reducing their migration and improving structural stability. This combined effect enhances both rate capability and reversibility. When coupled with lithium iron phosphate in a pouch cell, the composite negative electrode delivers a specific energy of 282 Wh kg-1 and retains 80% of its capacity after 10 min of charging at high specific current. The device also maintains stable operation over thousands of cycles, demonstrating improved durability under fast charging conditions.

Chemical bonding black phosphorus with TiO2 and carbon toward high-performance lithium storage

Metal phosphides as anode materials for alkali-metal ion batteries have captured considerable interest due to their high theoretical capacities and electronic conductivity. However, they suffer from huge volume expansion and element segregation during repetitive insertion/extraction of guest ions, leading to structure deterioration and rapid capacity decay. Herein, an amorphous Sn0.5Ge0.5P3 was constructed through a two-phase intermediate strategy based on the elemental composition modulation from two crystalline counterparts and applied in alkali-metal ion batteries. Differing from crystalline P-based compounds, the amorphous structure of Sn0.5Ge0.5P3 effectively reduces the volume variation from above 300% to 225% during cycling. The ordered distribution of cations and anions in the short-range ensures the uniform distribution of each element during cycles and thus contributes to durable cycling stability. Moreover, the long-range disordered structure of amorphous material shortens the ion transport distance, which facilitates diffusion kinetics. Benefiting from the aforementioned effects, the amorphous Sn0.5Ge0.5P3 delivers a high Na storage capacity of 1132 mAh g-1 at 0.1 A g-1 over 100 cycles. Even at high current densities of 2 and 10 A g-1, its capacities still reach 666 and 321 mAh g-1, respectively. As an anode for Li storage, the Sn0.5Ge0.5P3 similarly also exhibits better cycling stability and rate performance compared to its crystalline counterparts. Significantly, the two-phase transition strategy is generally applicable to achieving other amorphous metal phosphides such as GeP2. This work would be helpful for constructing high-performance amorphous anode materials for alkali-metal ion batteries.

Lithium-sulfur (Li-S) batteries have recently become a research hotspot because of their tempting theoretical capacity and energy density. Nevertheless, the notorious shuttle of polysulfides hinders the advancement of Li-S batteries. Herein, a two-dimensional covalent organic framework (COF) with extended π-conjugated units has been designed, synthesized, and used as sulfur recipients with 88.4 wt % in loading. The COF offers an elaborate platform for sufficient Li-S redox reactions with almost theoretical capacity release (1617 mA h g-1 at 0.1 C), satisfactory rate capability, and intensively traps polysulfides for a decent Coulombic efficiency (ca. 98.0%) and extremely low capacity decay (0.077% per cycle after 528 cycles at 0.5 C). The structural factors of the COF on the high-performance batteries are revealed by density functional theory calculations to be the high degrees of conjugation and proper interlayer space. This work not only demonstrates the great potential of COFs as highly efficient sulfur recipients but also provides a viable guidance for further design of COF materials to tackle shuttling issues toward active materials in electrochemical energy storage.