Anode Material For Potassium-ion Batteries Research Articles

Construction of Sugar-Gourd-Shaped Carbon Nanofibers Embedded with Heterostructured Zinc-Cobalt Selenide Nanocages for Superior Potassium-Ion Storage.

Transition metal selenides are considered as promising anode materials for potassium-ion batteries (PIBs) due to their high theoretical capacities. However, their applications are limited by low conductivity and large volume expansion. Herein, sugar-gourd-shaped carbon nanofibers embedded with heterostructured ZnCo-Se nanocages are prepared via a facile template-engaged method combined with electrospinning and selenization process. In this hierarchical ZnCo-Se@NC/CNF, abundant phase boundaries of CoSe2/ZnSe heterostructure can promote interfacial electron transfer and chemical reactivity. The interior porous ZnCo-Se@NC nanocage structure relieves volume expansion and maintains structural integrity during K+ intercalation and deintercalation. The exterior spinning carbon nanofibers connect the granular nanocages in series, which prevents the agglomeration, shortens the electron transport distance and enhances the reaction kinetics. As a self-supporting anode material, ZnCo-Se@NC/CNF delivers a high capacity (362mAhg-1 at 0.1Ag-1 after 100 cycles) with long-term stability (95.9% capacity retention after 1000 cycles) and shows superior reaction kinetics with high-rate K-storage. Energy level analysis and DFT calculations illustrate heterostructure facilitates the adsorption of K+ and interfacial electron transfer. The K+ storage mechanism is revealed by ex situ XRD and EIS analyses. This work opens a novel avenue in designing high-performance heterostructured anode materials with ingenious structure for PIBs.

Mechanistic exploration of Co doping in optimizing the electrochemical performance of 2H-MoS2/N-doped carbon anode for potassium-ion battery

The 2H-MoS2/nitrogen-doped carbon (2H-MoS2/NC) composite is a promising anode material for potassium-ion batteries (PIBs). Various transition metal doping has been adopted to optimize the poor intrinsic electronic conductivity and lack of active sites in the intralayer of 2H-MoS2. However, its optimization mechanisms have not been well probed. In this paper, using Cobalt (Co) as an example, we aim to investigate the influence of transition metal doping on the electronic and mechanical properties and electrochemical performance of 2H-MoS2/NC via first-principles calculation. Co doping is found to be effective in improving the electronic conductivity and the areas of active sites on different positions (C surface, interface, and MoS2 surface) of 2H-MoS2/NC. The increased active sites can optimize K adsorption and diffusion capability/processes, where general smaller K adsorption energies and diffusion energy barriers are found after Co doping. This helps improve the rate performance. Especially, the pyridinic N (pyN), pyrrolic N (prN), and graphitic N (grN) are first unveiled to respectively work best in K kinetic adsorption, diffusion, and interfacial stability. These findings are instructive to experimental design of high rate 2H-MoS2/NC electrode materials. The roles of different N types provide new ideas for optimal design of other functional composite materials.

Coupling Sb2WO6 microflowers and conductive polypyrrole for efficient potassium storage by enhanced conductivity and K+ diffusivity

Although metal oxide compounds are considered as desirable anode materials for potassium-ion batteries (PIBs) due to their high theoretical capacity, the large volume variation remains a key issue in realizing metal oxide anodes with long cycle life and excellent rate property. In this study, polypyrrole-encapsulated Sb2WO6 (denoted Sb2WO6@PPy) microflowers are synthesized by a one-step hydrothermal method followed by in-situ polymerization and coating by pyrrole. Leveraging the nanosheet-stacked Sb2WO6 microflower structure, the improved electronic conductivity, and the architectural protection offered by the PPy coating, Sb2WO6@PPy exhibits boosted potassium storage properties, thereby demonstrating an outstanding rate property of 110.3 mA h g−1 at 5 A g−1 and delivering a long-period cycling stability with a reversible capacity of 197.2 mA h g−1 after 500 cycles at 1 A g−1. In addition, the conversion and alloying processes of Sb2WO6@PPy in PIBs with the generation of intermediates, K2WO4 and K3Sb, is determined by X-ray photoelectron spectroscopy, transmission electron microscopy, and ex-situ X-ray diffraction during potassiation/depotassiation. Density functional theory calculations demonstrate that the robust coupling between PPy and Sb2WO6 endues it with a much stronger total density of states and a built-in electric field, thereby increasing the electronic conductivity, and thus effectively reduces the K+ diffusion barrier.

Two-Dimensional Biphenylene-Based Carbon Allotrope Family with High Potassium Storage Ability.

The development of new carbon materials with novel properties and excellent applications is essential and urgent in many fields, such as potassium-ion batteries (PIBs). In this study, a family of 30 two-dimensional biphenylene carbon allotropes (2D-BCAs) have been systematically extended in theory. The energies of these allotropes are slightly higher than that of graphene, which can be well described by a quantitative energy equation. The 2D-BCAs show high synthesizability consistent with the experimental biphenylene network via "HF-zipping" reactions. The 2D-BCAs are metallic or semimetallic. Six representative 2D-BCAs exhibit good lattice dynamical and thermal stability, excellent anisotropic mechanical properties, and ORR catalytic activity. Moreover, the selected 2D-BCAs demonstrate ultrahigh theoretical potassium-storage capacities of 1116-1489 mAh·g-1, low migration barriers of 0.03-0.22 eV, and low open-circuit voltages of 1.10-0.02 V. The remarkable properties render 2D-BCAs as promising anode materials in PIBs, electrocatalysts, and conductors in electronics and iontronics.

Multiple conductive network for KTi2(PO4)3 anode based on MXene as a binder for high-performance potassium storage

KTi2(PO4)3 is a promising anode material for potassium storage, but suffers from low conductivity and difficult balance between high capacity and good structural stability. Herein, the Ti3C2Tx MXene is used as a multifunctional binder to fabricate the KTi2(PO4)3 electrode by the traditional homogenizing-coating method. The MXene nanosheets, together with the conductive agent super P nanoparticles, construct a multiple conductive network for fast electron/ion transfer and high electrochemical kinetics. Moreover, the network ensures the structural stability of the KTi2(PO4)3 electrode during the de-intercalation/intercalation of 4 K+ ions, which is beneficial for simultaneously achieving high capacity and good cycle performance. Therefore, the MXene-bonded KTi2(PO4)3 electrode delivers a reversible capacity of 255.2 mAh/g at 50 mA/g, outstanding rate capability with 132.3 mAh/g at 2 A/g, and excellent cycle performance with 151.6 mAh/g at 1 A/g after 2000 cycles. This work not only suggests a high-performance anode material for potassium-ion batteries, but also demonstrates that the MXene is a promising binder material for constructing conductive electrodes in rechargeable batteries.

Recent progress on metal-organic framework derived carbon and their composites as anode materials for potassium-ion batteries

Potassium-ion batteries (PIBs) are considered as promising alternatives to lithium-ion batteries (LIBs) due to their abundant potassium resources, cost-effectiveness, and comparable electrochemical performance to LIBs. However, the practical application of PIBs is hindered by the slow dynamics and large volume expansion of anode materials. Owing to their unique morphology, rich pores, abundant active sites, and tunable composition, metal-organic framework (MOF)-derived carbon and its composites have been widely studied and developed as PIB anodes. In this review, the basic configuration, performance evaluation indicators, and energy storage mechanisms of PIBs were first introduced, followed by a comprehensive summary of the research progress in MOF-derived carbon and its composites, especially the design strategies and different types of composites. Moreover, the advances of in situ characterization techniques to understand the electrochemical mechanism during potassiation/depotassiation were also highlighted, which is crucial for the directional optimization of the electrochemical performance of PIBs. Finally, the challenges and development prospects of MOF-derived carbon and its composites for PIBs are prospected. It is envisioned that this review will guide and inspire more research efforts toward advanced MOF-derived PIB anode materials in the future.

A dual-carbon structured molybdenum selenide composites controlled via interface engineering and chemical bonding to attain high initial coulombic efficiency and rate capability of potassium-ion batteries

Molybdenum selenide (MoSe2) is considered representative anode material for Potassium-ion batteries (PIBs) by reason of its adjustable forbidden bandwidth and large interlayer spacing allowing the intercalation/deintercalation of large-sized K+. However, its inferior electronic conductivity, substantial volume variation, and aggregation make it difficult to achieve satisfactory cycling performance and rate capability. Herein, we reported a novel composite with MoSe2 nanosheets grown vertically on the surface of N-doped hollow porous carbon bowls and wrapped by ultrathin/wrinkled reduced graphene oxide layers (G-MoSe2/NHPCB) as the anode material for PIBs. The strong chemical bonds between MoSe2 and carbon materials (including C-Mo, C-O-Mo, and C-N-Mo bonds) were profitable for the charge-transfer kinetics and structural durability. The NHPCB substrate, with a large specific surface area, could significantly prohibit the aggregation of MoSe2 nanosheets and shorten the transmission path for electrons and ions. Meanwhile, the ultrathin/wrinkled graphene layers could effectively strengthen the composite structure stability and reinforce the overall conductivity. Benefitting from the distinctive structure, when evaluated as a K-ion half-cell anode, the G-MoSe2/NHPCB electrode exhibited a high discharge capacity of 601.59 mA h g−1 and initial coulombic efficiency (ICE) of 83.4% at 0.1 A/g, exceptional rate capability (261.3 mA h g−1 at 5.0 A/g) and long-term cycling stability (304.3 mA h g−1 at 1.0 A/g after 500 cycles and 214.9 mA h g−1 at 2.0 A/g after 1000 cycles). The electrochemical reaction mechanism and kinetic analysis were investigated using in-situ and ex-situ methods and first-principles calculation. This work demonstrates the advantages of G-MoSe2/NHPCB as KIBs anode materials and provides innovative thinking for the rational design of high-performance transition metal selenides with unique structures.

Crystallization-induced thickness tuning of carbon nanosheets for fast potassium storage

Carbon nanosheets (CNS) have garnered significant interest as anode materials for potassium-ion batteries (PIBs) due to the excellent potassium storage kinetics and rate performance. Moreover, tuning the thickness of CNS can enhance the potassium storage performance by exposing abundant surface active sites and shortening the K+ migration path. Herein, crystallization-induced thickness tuning of carbon nanosheets in polyvinyl pyrrolidone-potassium chloride (PVP-KCl) solution is reported to enhance the fast potassium storage. PVP with varying molecular weights is employed to induce the crystallization behavior of KCl, leading to the formation of KCl grains with controllable sizes. Concurrently, these KCl grains act as hard templates for dispersing the PVP molecules to fabricate carbon nanosheets on the surface during annealing. PVP with high molecular weight is beneficial for hindering ion migration to reduce crystal sizes, which can decrease the thickness of carbon nanosheets. The ultrathin structure exposes abundant potassium storage sites, endowing CNS with high reversible capacity (359.0 mAh/g at 100 mA/g). The reduction in the migration path of K+ ions facilitate rapid ion and electron transport kinetics, resulting in rate performance with a capacity of 181.9 mAh/g at 1 A/g. Our work extends the application of the crystallization-induced strategy for controllable designing carbon nanosheets, and puts forward some conceptions on improving the potassium storage performance of carbon anode materials.

Metallic BSi3 monolayer as a high rate-capacity anode material for flexible potassium ion batteries: A first-principles study

Potassium ion batteries (PIBs) have attracted great attention as a competitive substitute for lithium ion batteries (LIBs) because of the good safety and low cost; nevertheless, their practical application is severely impeded by the lack of a high-performance anode material. Motivated by the high capacity of silicon and excellent stability of boron, we investigate a 2D B-Si binary compound (h-BSi3 and o-BSi3) as the anode material of PIBs. Our first-principles calculation results demonstrate that BSi3 monolayers have the intrinsic metallicity with high electrical conductivity, which is of great importance for the rapid electronic transport during electrochemical process. Benefitting from the strong affinity of potassium, the h-BSi3 (o-BSi3) anode achieves a high specific capacity of 1268.45 (1190.15) mA h/g and a low averaged open circuit voltage of 0.38 (0.48) V. The potassium diffusion barrier on the h-BSi3 (o-BSi3) anode is as low as 0.02 (0.04) eV. Moreover, a small lattice expansion is observed for the BSi3 anodes without metal dendrite formation at the final potassiated stage, which is beneficial to prolong the cycle life of PIBs. All the unique features suggest that BSi3 monolayers are promising anode candidates for flexible PIBs.

Theoretical prediction of metallic R12-graphene as a promising anode material for potassium-ion batteries with high ion mobility, high capacity, and excellent electrolyte wettability

Although graphene has excellent electrical and mechanical properties, the giant delocalized π-electron system makes it chemically inert. Here, we propose an idea to design two-dimensional (2D) carbon allotropes via incorporating multiple rings in sp2-hybridized carbon networks, which can break the π-bonding network and enhance the surface reactivity. By assembling molecule of cyclobut(a)acenaphthylene, we predict a monolayer 2D carbon material, named as R12-graphene, which is composed of quadrilateral, pentagonal, hexagonal, and dodecagonal carbon rings. It shows great stability in energetic, dynamic, thermodynamic, and mechanical aspects. It exhibits high-performance as an anode material for potassium-ion batteries (PIBs), including an intrinsic metallic behavior, a high theoretical capacity (632 mA h g−1), a low K diffusion barrier (0.33 eV), and a low average open-circuit voltage (0.5 V). The presence of electrolytes can provide better K ion adsorption and diffusion capability compared to that in vacuum. Furthermore, R12-graphene has excellent wettability toward some commonly used electrolytes, which is beneficial for improving the charge/discharge rate for PIBs.

Sustainable Polyvinyl Chloride-Derived Soft Carbon Anodes for Potassium-Ion Storage: Electrochemical Behaviors and Mechanism.

Soft carbon is a promising anode material for potassium-ion batteries due to its favorable properties such as low cost, high conductivity, stable capacity, and low potential platform. Polyvinyl chloride, as a white pollutant, is a soft carbon precursor that can be carbonized at varying temperatures to produce soft carbons with controllable defect and crystal structures. This work investigates the effect of carbonization temperature on the crystalline structures of the obtained soft carbons. In situ Raman spectroscopy was used to elucidate the adsorption-intercalation charge storage mechanism of potassium ions in soft carbons. Soft carbons prepared at the temperature of 800 °C have a defect-rich, short-range ordered structure, which provides optimal intercalation and adsorption sites for potassium ions, resulting in a satisfactory capacity of 302 mAh g-1 . This work presents new possibilities for designing soft carbon materials from recycling plastics for potassium-ion batteries.

Bismuth Telluride Nanoplates Hierarchically Confined by Graphene and N-Doped C as Conversion-Alloying Anode Materials for Potassium-Ion Batteries.

Potassium-ion batteries (PIBs) have broad application prospects in the field of electric energy storage systems because of its abundant K reserves, and similar "rocking chair" operating principle as lithium-ion batteries (LIBs). Aiming to the large volume expansion and sluggish dynamic behavior of anode materials for storing large sized K-ion, bismuth telluride (Bi2 Te3 ) nanoplates hierarchically encapsulated by reduced graphene oxide (rGO), and nitrogen-doped carbon (NC) are constructed as anodes for PIBs. The resultant Bi2 Te3 @rGO@NC architecture features robust chemical bond of Bi─O─C, tightly physicochemical confinement effect, typical conductor property, and enhanced K-ion adsorption ability, thereby producing superior electrochemical kinetics and outstanding morphological and structural stability. It is visually elucidated via high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) that conversion-alloying dual-mechanism plays a significant role in K-ion storage, allowing 12 K-ion transport per formular unit employing Bi as redox site. Thus, the high first reversible specific capacity of 322.70mAhg-1 at 50mAg-1 , great rate capability and cyclic stability can be achieved for Bi2 Te3 @rGO@NC. This work lays the foundation for an in-depth understanding of conversion-alloying mechanism in potassium-ion storage.

Two-Dimensional Molecular Brush-Based Ultrahigh Edge-Nitrogen-Doped Carbon Nanosheets for Ultrafast Potassium-Ion Storage

Heteroatom doping, especially nitrogen doping, has been regarded as an efficient strategy to break through the capacity limitation of carbonaceous anode materials in potassium-ion batteries (PIBs). Constructing edge-nitrogen-rich carbon skeleton with highly exposed active sites and efficient charge transfer is critical for the high performance of nitrogen-doped carbonaceous anode materials. Herein, a kind of ultrahigh edge-nitrogen (up to 16.2 at%) doped carbon nanosheets (ENCNS) has been developed by an efficient assembly of high-nitrogen-ratio melamine (MA) with polyacrylic acid grafted graphene oxide (GO-g-PAA) molecular brushes. The assembled PAA/MA structure facilitates the formation of an edge-nitrogen-rich carbon skeleton during heat treatment, while the highly conductive graphene backbone with a 2D nanomorphology enables shortened ion diffusion pathways and numerous exposed active surfaces. As a result, the ENCNS demonstrate excellent rate performance (up to 144 mAh g−1 at 10 A g−1) and good cycle stability (136 and 100 mAh g−1 after 400 cycles at 5 and 10 A g−1, respectively).

Design of multifunctional graphene oxide-modified nanofiber film with heterostructure (ZnS-CoS@GO@CNFs) for long-term stable potassium ion storage

When transition metal sulfides are used as high-theoretical-capacity anodes for potassium ion batteries (PIBs), their low conductivity and large volume expansion resulted in inferior rate performance and cyclic stability. In this study, multifunctional graphene oxide (GO) was employed to control the diameter and distribution of nanoparticles within composite fibers, which improved their conductivity and tensile deformation. In addition, a three-dimensional conductive carbon network composed of heterostructures and GO (ZnS-CoS@GO@CNFs) accelerated the kinetics and stabilized potassium ion storage. As the anode material of PIBs, the composite provided an excellent rate performance of 210 mA h g−1 at 3 A g−1, and after 2800 cycles under a large current of 2 A g−1, the capacity retention rate was 97.7% (171 mA h g−1). Furthermore, when the nanofiber film was used as a self-supporting anode, it maintained a stable capacity output (302 mA h g−1 after 100 cycles at 0.1 A g−1). A foldable pouch cell was assembled using a potassium ion hybrid super-capacitor, and it was found to operate safely and normally under multiangle repeated bending and final recovery; further, it provided a high energy density (134 W h kg−1) and power density (5815 W kg−1). The excellent electrochemical properties determined here further reveal the application prospects of multifunctional GO composite fiber film.

Low-Strain KVPO4F@C as Hyperstable Anode for Potassium-Ion Batteries

Potassium-ion batteries with carbon-based materials and alloy materials as anodes possess pronounced potassium storage and cycling abilities, yet they suffer from harsh synthetic processes, low initial Coulombic efficiency, and limited structure stability. Herein, we first put forward potassium vanadium fluorophosphate (KVPO4F) as a highly stable anode material for potassium-ion batteries (PIBs). KVPO4F@C composite is successfully synthesized through hydrothermal method followed by a low-temperature roasting process. An amorphous carbon film is homogeneously wrapped on the surface of the KVPO4F particles to improve electronic conductivity. As the anode for PIBs, the KVPO4F@C presents a super-high discharge capacity of 242.32 mAh g−1 and a superior cycle stability over 120 cycles at 100 mA·g−1 with 93.1% capacity retention. Additionally, it maintains 92.9% of its initial capacity of 100 mA·g−1 at 1000 mA·g−1 after cycling 2100 times, which indicates an excellent long cycling performance. The in situ X-ray Diffraction and ex situ Transmission Electron Microscopy tests prove the minimal volume variation and stable structure of KVPO4F@C. The designed KVPO4F@C provides facilitative electronic conductivity and stable structure, successfully innovating an ultra-stable and high-performance anode material for potassium-ion batteries and other energy storage application fields.

A Novel Hexaazatriphenylene Carboxylate with Compatible Binder as Anode for High‐Performance Organic Potassium‐Ion Batteries

AbstractOrganic electrode materials have attracted tremendous attention for potassium‐ion batteries (PIBs). Whereas, high‐performance anodes are scarcely reported. Herein, a novel hexaazatriphenylene potassium carboxylate (HAT‐COOK) is proposed as anode materials for PIBs. The rich CN/CO bonds guarantee the high theoretical capacity. It is also demonstrated HAT‐COOK is more compatible with the water‐soluble binders than the hydrophobic fluoride binders, forming homogenous electrode film, maintaining structural integrity, and achieving stable cycling and excellent rate performance. With the compatible binder, each HAT‐COOK molecule can involve 6‐electron transfer, yielding a high reversible discharge capacity of 288 mAh g−1 at 50 mA g−1, excellent rate performance (105 mAh g−1 at 5000 mA g−1), and good cycling stability (143 mAh g−1 after 500 cycles at 500 mA g−1). These results highlight the importance of the delicate molecular design of organic molecules as well as the optimization of binders to achieve high‐performance PIBs.

Hierarchical construction of MoSe2 nanoparticles anchored on N-doped porous carbon nanocages with Mo-C bonding for enhanced potassium-ion storage

Molybdenum selenide (MoSe2) is considered as a promising anode material for potassium ion batteries (PIBs) due to its high theoretical capacity and large interlayer spacing. However, the low intrinsic conductivity and large volume expansion impede its practical application. Herein, hierarchical nanostructure of MoSe2 nanoparticles tightly anchored on hollow porous nitrogen-doped carbon nanocages (MoSe2/NCC) is constructed as an anode material for PIBs. Nitrogen-doped carbon nanocages not only improve the conductivity, provide more active sites, and alleviate the volume expansion during K+ insertion and desertion, but also serve as a nucleation substrate for suppressing the agglomeration of MoSe2 nanoparticles. Importantly, the structural stability and electron/ion transfer kinetics are significantly enhanced by strong interfacial coupling between MoSe2 and carbon via the formation of Mo-C bonding. Consequently, MoSe2/NCC electrode exhibits a reversible capacity of 321 mA h g−1 at 0.1 A g−1, excellent cycling stability with a retention of 323 mA h g−1 after 80 cycles, and rate capability of 173 mA h g−1 at 5 A g−1. In addition, the storage mechanism and transfer kinetics of potassium ions during the charging and discharging process are investigated. This work paves the ideas for the design of novel anode materials for high-rate and stable PIBs.

Ultrarapid Nanomanufacturing of High-Quality Bimetallic Anode Library toward Stable Potassium-Ion Storage.

Bimetallic alloy nanomaterials are promising anode materials for potassium-ion batteries (KIBs) due to their high electrochemical performance. The most well-adopted fabrication method for bimetallic alloy nanomaterials is tube furnace annealing (TFA) synthesis, which can hardly satisfy the trade-off among granularity, dispersity and grain coarsening due to mutual constraints. Herein, we report a facile, scalable and ultrafast high-temperature radiation (HTR) method for the fabrication of a library of ultrafine bimetallic alloys with narrow size distribution (≈10-20 nm), uniform dispersion and high loading. The metal-anchor containing heteroatoms (i.e., O and N), ultrarapid heating/cooling rate (≈103 K s-1 ) and super-short heating duration (several seconds) synergistically contribute to the successful synthesis of small-sized alloy anodes. As a proof-of-concept demonstration, the as-prepared BiSb-HTR anode shows ultrahigh stability indicated by negligible degradation after 800 cycles. The in situ X-ray diffraction reveals the K+ storage mechanism of BiSb-HTR. This study can shed light on the new, rapid and scalable nanomanufacturing of high-quality bimetallic alloys toward extended applications of energy storage, energy conversion and electrocatalysis.

Constructing sulfur and oxygen co-doped carbon nanosheets by tailoring poly tannic acid for fast and stable potassium storage

Carbonaceous material with excellent structural stability and low cost has always been deemed focus of pursuer, nevertheless it showed the sluggish dynamics and large volume expansion as the anode materials for potassium-ion batteries (PIBs). Herein, S, O co-doped ultra-thin carbon nanosheets (S/O-CNS) with enlarged interlayer spacing was synthesized through pyrolysis poly tannic acid with a sulfur-assisted carbonization strategy. Under the unique synthesis process, sulfur acts as a dopant and intercalating agent to acquire few-layer carbon nanosheets with large interlayer spacing (0.42 nm), while oxygen was in-situ doped into the carbon lattice and provides sites for sulfur doping. With the synergistic effects of the co-doping effect and heterostructure, S/O-CNS delivers an excellent reversible capacity of 375.6 mA h g−1 at 0.1 A g−1, an impressive rate performance of 159.9 mA h g−1 even at 10 A g−1 as well as outstanding cycle stability of 198.9 mA h g−1 after 700 cycles at 1.0 A g−1. Kinetics analysis indicates that the capacitance-controlled process plays a dominant role in K+ storage. The results prove that the enlarged interlayer spacing and abundant edge defects accelerate the ion diffusion kinetics. This dual-doping strategy provides a way to design high-performance carbonaceous materials for PIBs.

KOH-treated mesocarbon microbeads used as high-rate anode materials for potassium-ion batteries

KOH-treated mesocarbon microbeads used as high-rate anode materials for potassium-ion batteries