Anode For Rechargeable Batteries Research Articles

General Fabrication of Robust Alloyed Metal Anodes for High-Performance Metal Batteries.

Revitalizing metal anodes for rechargeable batteries confronts challenges such as dendrite formation, limited cyclicity, and suboptimal energy density. Despite various efforts, a practical fabrication method for dendrite-free metal anodes remains unavailable. Herein, focusing on Li as exemplar, a general strategy is reported to enhance reversibility of the metal anodes by forming alloyed metals, which is achieved by induction heating of 3D substrate, lithiophilic metals, and Li within tens of seconds. It is demonstrated that preferred alloying interactions between substrates and lithiophilic metals created a lithiophilic metal-rich region adjacent to the substrate, serving as ultrastable lithiophilic host to guide dendrite-free deposition, particularly during prolonged high-capacity cycling. Simultaneously, an alloying between lithiophilic metals and Li creates a Li-rich region adjacent to electrolyte that reduces nucleation overpotential and constitutes favorable electrolyte-Li interface. The resultant composite Li anodes paired with high areal loading LiNi0.8Co0.1Mn0.1O2 cathodes achieve superior cycling stability and remarkable energy density above 1200 Wh L-1 (excluding packaging). Furthermore, this approach shows broader applicability to other metal anodes plagued by dendrite-related challenges, such as Na and Zn. Overall, this work paves the way for development of commercially viable metal-based batteries that offer a combination of safety, high energy density, and durability.

Driving inward growth of lithium metal in hollow microcapsule hosts by heteroatom‐controlled nucleation

AbstractThe application of Li metal anodes in rechargeable batteries is impeded by safety issues arising from the severe volume changes and formation of dendritic Li deposits. Three‐dimensional hollow carbon is receiving increasing attention as a host material capable of accommodating Li metal inside its cavity; however, uncontrollable and nonuniform deposition of Li remains a challenge. In this study, we synthesize metal–organic framework‐derived carbon microcapsules with heteroatom clusters (Zn and Ag) on the capsule walls and it is demonstrated that Ag‐assisted nucleation of Li metal alters the outward‐to‐inward growth in the microcapsule host. Zn‐incorporated microcapsules are prepared via chemical etching of zeolitic imidazole framework‐8 polyhedra and are subsequently decorated with Ag by a galvanic displacement reaction between Ag+ and metallic Zn. Galvanically introduced Ag significantly reduces the energy barrier and increases the reaction rate for Li nucleation in the microcapsule host upon Li plating. Through combined electrochemical, microstructural, and computational studies, we verify the beneficial role of Ag‐assisted Li nucleation in facilitating inward growth inside the cavity of the microcapsule host and, in turn, enhancing electrochemical performance. This study provides new insights into the design of reversible host materials for practical Li metal batteries.

Unveiling The Mechanism of The Dendrite Nucleation and Growth in Aqueous Zinc Ion Batteries

AbstractAqueous zinc ion batteries (ZIBs) exhibit great potential for next‐generation energy storage devices. However, significant challenges exist, including the uncontrollable formation of Zn dendrite and side reactions during zinc stripping and plating. The mechanism of Zn dendrite nucleation has yet to be fully understood. In this work, the first principles simulations are used to investigate the Zn dendrite formation process. The unintentionally adsorbed O2− and OH− ions are the inducing factors for Zn dendrite nucleation and growth on the Zn (0001) plane due to significantly increased Zn diffusion barriers. A top‐down method is demonstrated to suppress the dendrite using delaminated V2CTx to capture O2− and OH− ions thanks to reduced Zn diffusion barriers. The experimental results revealed significantly suppressed Zn dendrite nucleation and growth, resulting in a layer‐by‐layer deposit/stripping of Zn. Based on the electrochemical evaluations, the V2CTx‐coated Zn composite delivers a high coulombic efficiency of 99.3% at 1.0 mAh cm−2. Furthermore, the full cell achieves excellent cyclic performance of 93.6% capacity retention after 2000 cycles at 1 A g−1. This strategy has broad scalability and can be widely applied in designing metallic anodes for rechargeable batteries.

Design Principles for Heterointerfacial Alloying Kinetics at Metallic Anodes in Rechargeable Batteries

How surface chemistry influences reactions occurring thereupon has been a long-standing question of broad scientific and technological interest. Here we consider the relation between the surface chemistry at such interfaces and the reversibility of electrochemical transformations at rechargeable battery electrodes. Using Zn as a model system, we report that a moderate strength of chemical interaction between the deposit and the substrate—neither too weak nor too strong—enables highest reversibility and stability of the plating/stripping redox processes. Focused-ion-beam and electron microscopy were used to directly probe the morphology, chemistry and crystallography of the heterointerfaces of distinct natures. Analogous to the empirical Sabatier principle for chemical heterogeneous catalysis, our finding arises from the confluence of competing interfacial processes. Using full batteries with stringent N:P ratios, we show that such knowledge provides a powerful tool for designing key materials in highly reversible battery systems based on earth-abundant, low-cost metals such as Zn and Na.Reference: Zheng, Jingxu, et al. "Design principles for heterointerfacial alloying kinetics at metallic anodes in rechargeable batteries." Science Advances 8.44 (2022): eabq6321.

Safe Solvent-in-Salt Electrolytes for Dendrite-Free Zinc Metal Batteries

As global markets for electric vehicles (EV) and energy storage systems (ESS) expand rapidly, there are growing needs to develop alternative battery systems to replace current lithium-ion battery (LIBs) technology, which suffers from high material cost, and insufficient safety. Rechargeable zinc batteries have emerged as one of the most viable and sustainable candidates to replace LIB owing to various beneficial features of zinc such as natural abundance, easy recyclability (by electrowinning), high safety and high volumetric capacity (5,854 Ah/L) compared with lithium (2,062 Ah/L). However, parasitic side reactions such as spontaneous Zn corrosion & hydrogen evolution, and unregulated dendritic growth of Zn deposit may occur in the aqueous electrolytes, which may eventually degrade the battery performance and safety seriously. In this work, we focus on an alternative method for regulating the morphological development of the Zn metal deposit using highly-concentrated organic electrolytes, which exhibits particular physicochemical properties such as high electrochemical window, high stability, and non-flammability. We will show that it does not only suppress the formation of dendrite effectively during Zn plating-stripping process via regulating the crystal growth of Zn deposits, but also hold a flame-retarding property, thereby making it appropriate as a highly-safe anode for rechargeable batteries. This study proposed a new strategy of making a battery with dendrite-free operation, high stability, and a long cycle-life by controlling the crystal facet of a Zn metal deposit using highly-concentrated organic electrolytes. Keywords: Zinc metal, highly-concentrated organic electrolytes, dendrite-free, high redox stability Acknowledgments This work was supported by the KIST institutional program (KIST-2E32582) and the National Research Foundation of Korea (NRF-2021R1A2C2008680)

Molten Salt Based High Entropy Electrolytes for Calcium Batteries

Calcium (Ca) is in principle a very attractive metal anode for rechargeable batteries due to the large abundance of calcium in the Earth’s crust, its low electrochemical potential, and its low cost1. Until rather recently2, however, stable plating and stripping of Ca and hence rechargeability of Ca-batteries was deemed impossible, due to the stable phases formed at the electrolyte/electrode interface, completely blocking Ca2+ transfer3.Since this pivotal breakthrough, Ca-batteries have attracted more interest, but they are still in their very infancy and new battery designs – such as using novel electrolyte concepts – are needed to achieve stable cycling of Ca metal anodes, and this preferably at room temperature.Here we report on the use of molten salt electrolytes, i.e. binary and multi-component systems of inorganic cations and anions, and more specifically on their physico-chemical and electrochemical properties as a function of composition with special emphasis on the compositional entropy. By using completely solvent-free electrolytes issues associated with organic electrolytes and solvents, such as the blocking of Ca2+ transfer and electrolyte flammability3, are avoided. Furthermore, they should/do not induce any large polarization, as opposed to ionic liquid-based electrolytes4.In more detail, using the Ca(FSI)2 salt in combination with the analogous Li-, Na-, and KFSI salts in equimolar compositions, all with melting temperatures (significantly) above 100 °C, we can create electrolytes melting at ca. 60-75 °C for the ternary systems, which is further reduced to ca. 55 °C for the quaternary system. These lowered melting temperatures are achieved by increased entropy of mixing, reducing the Gibbs free energy. This can for example be illustrated by Raman spectroscopy via comparing the spectra of “as cast” electrolytes with the spectra for the ones “aged” for one week (Figure 1). Here the FSI anion band at 772 cm-1 (νsS-N-S)5 shows that the electrolytes partially (re-)crystallize/micro-separate for the ternary systems, but stay more stable for the quaternary system, which we, at least partially, attribute to an entropy effect. Reference s M. E. Arroyo-De Dompablo, A. Ponrouch, P. Johansson, and M. R. Palacín, Chem . Rev., 120, 6331–6357 (2020).A. Ponrouch, C. Frontera, F. Bardé, and M. R. Palacín, Nat. Mater., 15, 169–172 (2016).D. Aurbach, R. Skaletsky, and Y. Gofer, J . Electrochem Soc., 138, 3536–3545 (1991).Q. Pang et al., Nature, 608, 704–711 (2022).K. Matsumoto, T. Oka, T. Nohira, and R. Hagiwara, Inorg . Chem ., 52, 568–576 (2013). Figure 1

A Review on Covalent Organic Frameworks as Artificial Interface Layers for Li and Zn Metal Anodes in Rechargeable Batteries.

Li and Zn metals are considered promising negative electrode materials for the next generation of rechargeable metal batteries because of their non-toxicity and high theoretical capacity. However, the uneven deposition of metal ions (Li+ , Zn2+ ) and the uncontrolled growth of dendrites result in poor electrochemical stability, unsatisfactory cycle life, and rapid capacity decay of batteries assembled with Li and Zn electrodes. Owing to the unique internal directional channels and abundant redox active sites of covalent organic frameworks (COFs), they can be used to promote uniform deposition of metal ions during stripping/electroplating through interface modification strategies, thereby inhibiting dendrite growth. COFs provide a new perspective in addressing the challenges faced by the anodes of Li metal batteries and Zn ion batteries. This article discusses the stability and types of COFs, and summarizes some novel COF synthesis methods. Additionally, it reviews the latest progress and optimization methods of using COFs for metal anodes to improve battery performance. Finally, the main challenges faced in these areas are discussed. This review will inspire future research on metal anodes in rechargeable batteries.

3D Cu Pyramid Array Grown on Planar Cu Foil for Stable and Dendrite-free Lithium Deposition

Lithium metal is recognized as the anticipated anode for rechargeable batteries because of its inherent physicochemical properties. Unfortunately, the industrialization of Li metal anodes (LMAs) has been entangled in some intractable problems stemming from the uncontrollable growth of Li dendrites, which could result in the issue of short-circuit, thereby leading to cell failure. Here, a three-dimensional structured Cu pyramid array (CPA@CF) is constructed on planar Cu foil (CF) by the simple electrodeposition method. Owing to the features of large surface area and 3D porous structure, the proposed CPA@CF not only can promote Li-ion diffusion and charge transfer, but also effectively slow down the volume change of Li. Consequently, an even and steady Li plating/stripping process up to 360 h is realized using such a CPA@CF current collector. The Li@CPA@CF|LiFePO4 full cell achieves an excellent Coulombic efficiency (CE) of 99.3 % for 160 cycles at 0.3 C with a superior capacity retention of 84.2 %.

Towards Safer All-Solid-State Lithium Metal Batteries by an Artificial Protection Layers

Lithium ion batteries (LIB) are representing a milestone in electrochemical energy storage and are still the state-of-the-art battery system for various mobile and stationary energy storage applications. However, the practical energy density of LIBs starts to reach an asymptotic limit. Beside LIBs, an auspicious variety of battery systems comprising a better option for specific applications in terms of e.g. energy density, so establishing a diversity of specific battery systems for specific applications is a good strategy.[1 ] After initially paving the way for the LIB, the lithium metal battery (LMB) experiences a revival due to an outstanding theoretical specific capacity (3 860 mAh g−1) and low electrochemical potential (−3.04 V vs. SHE). However, continuous electrolyte consumption, the formation of an inhomogeneous SEI and high surface area lithium (HSAL), whose growth is induced by the heterogeneous and fragile structure of the SEI film, are still dominant challenges that need to be overcome. The liquid electrolytes also deal with safety issues like risk of leakage and flammability. The combination of Li metal with solid polymer electrolytes (SPE) could supress HSAL formation and avoid those safety hazards. However, SPEs deal with poor ionic conductivity at room temperature (10−8 S cm−1 ≤ σ ≤ 10−5 S cm−1) and, additionally, it is necessary to control the Li morphology during electrodeposition/dissolution to realize high-energy all-solid-state batteries (ASSB) based on Li metal anodes.[2 ,3 ] Several artificial protective coatings have been proposed to improve the LMA/SPE interface by facilitating the Li ion flux, promoting a homogeneous Li electrodeposition/dissolution and protecting the LMA against electrolyte degradation as well as enhancing the Li wetting interface. The SPE induces a more flexible interphase that withstands the volume change. Recently, metal oxides coated by atomic layer deposition (ALD) have gained attention due to a great thickness control, the possibility of monolayer deposition as well as a consequential homogeneity of the deposited protection layer. Furthermore, ALD is suitable for roll-to-roll coatings which is feasible for industrial application.[3,4 ] Herein, the setup of Li-metal-polymer batteries (LMP® technology) commercialized by Blue Solutions and applied in their “blue cars” (30 kWh, 100 Wh kg-1) was modified in several points. Li metal was coated with a metal oxide via atomic layer deposition (ALD) to form an intermetallic phase as protective layer and to improve the Li+ flux. The artificial protective coating at Li metal was combined with a PEO- and/or polyether-based SPE and the effect of the modifications on the electrochemical performance in different ASSB setups was investigated and characterized.[1] Placke, T.; Kloepsch, R.; Dühnen, S.; Winter, M. Lithium ion, lithium metal, and alternative rechargeable battery technologies: the odyssey for high energy density. Journal of Solid State Electrochemistry 2017, 21, 1939-1964.[2] Cheng, X.-B.; Zhang, R.; Zhao, C.-Z.; Zhang, Q. Toward Safe Lithium Metal Anode in Rechargeable Batteries: A Review. Chemical Reviews 2017, 117, 10403-10473.[3] Han, Z.; Zhang, C.; Lin, Q.; Zhang, Y.; Deng, Y.; Han, J.; Wu, D.; Kang, F.; Yang, Q. H.; Lv, W. A Protective Layer for Lithium Metal Anode: Why and How. Small Methods 2021, 5, 2001035.[4] Han, Y.; Liu, B.; Xiao, Z.; Zhang, W.; Wang, X.; Pan, G.; Xia, Y.; Xia, X.; Tu, J. Interface issues of lithium metal anode for high‐energy batteries: Challenges, strategies, and perspectives. InfoMat 2021, 3, 155-174.

Self-healing Ga-based liquid metal/alloy anodes for rechargeable batteries

Self-healing Ga-based liquid metal/alloy anodes for rechargeable batteries

Self-assembled ZrO2 hollow nanospheres as high-performance anode for rechargeable batteries

A facile soft-template self-assembly strategy is reported to synthesize monodispersed ZrO2hollow nanospheres of size 28 ± 2 nm as a candidate for anode material in lithium-ion batteries (LIBs). Triblock copolymeric micelles of poly (styrene-b-2-vinyl methylpyridinium iodide-b-ethylene oxide) (PS-PVMP-PEO) with core–shell-corona architecture serve as an efficient scaffold for the synthesis of ZrO2hollow nanospheres using Zr(IV) butoxide as metal source. The ZrO2hollow nanostructured electrode delivers a stable capacity of 97 mAh.g−1after 100 repeated charge/discharge cycles at a high current density of 1C rate, which is four-fold higher than that observed for dense ZrO2.

In situ tracking of the lithiation and sodiation process of disodium terephthalate as anodes for rechargeable batteries by Raman spectroscopy

In situ tracking of the lithiation and sodiation process of disodium terephthalate as anodes for rechargeable batteries by Raman spectroscopy

Dynamic Galvanic Corrosion of Working Lithium Metal Anode Under Practical Conditions

AbstractThe practical deployment of lithium metal anodes in rechargeable batteries has been significantly restricted by poor electrochemical performance, which largely stemms from their high susceptibility to corrosion. Inan effort to complete the real picture of Li corrosion pathways, in this contribution, a dynamic galvanic corrosion mechanism under realistic working conditions is described, through which an extended solid electrolyte interphase (SEI) is progressively generated on the successively exposed copper substrate during the dynamic Li removal process. As determined by the titration gas chromatography method, the dynamic galvanic corrosion reaction is unveiled to induce an unfavorable extra Li loss and hence a reduced cell reversibility, especially at sluggish Li stripping rates. Systematic investigations reveal that three critical factors, including total step length of Li stripping, dynamic corrosion current (icorrosion) degradation speed, and SEI chemistry, are responsible form odulating the extent of dynamic galvanic corrosion in practical batteries. This work provides an important complement to current knowledge regarding the corrosion processes of working Li metal anodes, affording fresh insights into the design strategies toward high‐reversibility Li cycling.

Black phosphorus stabilized by titanium disulfide and graphite via chemical bonds for high-performance lithium storage

Black phosphorus (BP) anode has received extensive attentions for lithium-ion batteries (LIBs) due to its ultrahigh theoretical specific capacity (2596 mAh g−1) and superior electronic conductivity (≈102 S m−1). However, the enormous volume variations during lithiation/delitiation processes greatly limit its applications. Herein, a new BP-titanium disulfide-graphite (BP-TiS2-G) nanocomposite composed of BP, titanium disulfide and graphite has been prepared by a facile and scalable high-energy ball milling method. The experimental data proves that PC and PS bonds have been successfully introduced at the interface, which can effectively maintain the structural integrity of the BP-TiS2-G electrode when evaluated as an anode material for LIBs. In addition, lithium-ion diffusion kinetics have been demonstrated to be enhanced from the synergistic effect of PC and PS bonds. As a result, the BP-TiS2-G anode shows outstanding cycling stability (906.2 mAh g−1 after 1300 cycles at 1.0 A g−1) and superior rate performance (313.8 mAh g−1 at 10.0 A g−1). Our work shows the synergistic effects of different chemical bonds to stabilize BP can be a potential strategy for the development of high-performance alloy-type anodes for rechargeable batteries.

Room-Temperature Rapid Self-Healing Polymer Binders for Si Anodes in Highly Cycling-Stable and Capacity-Maintained Lithium-Ion Batteries

Silicon (Si) with high specific capacity has received increasing attention for rechargeable battery anode materials. However, particle pulverization as a result of the large volume expansion of Si anodes further aggravated electrochemical performance degradation during the process of charging and discharging. In this work, we report the room-temperature rapid self-healing polymer binders (Al/Alg-TUEG) synthesized via dynamic coordination bonds (Al–O) and hydrogen bonds from poly(ether-thioureas) (TUEG). The prepared polymer binders exhibit a peeling force of 4.2 N, a swelling ratio of 9.5%, and a recovery of 90% in 2 h at room temperature. As a result, the Si@Al/Alg-TUEG anodes stably cycle for 300 cycles at 0.5 C with a capacity retention rate of 77.4%. A high initial Coulombic efficiency (CE) of 87.2% and good rate performance are also achieved. In terms of full cell performance, both LiFePO4//Si@Al/Alg-TUEG and NCM811//Si@Al/Alg-TUEG display stable cycling for 100 cycles at 0.5 C. The capacity retention of both full cells reaches 93.8 and 92.5%. Good recoverability at high rates is also found. The superior electrochemical performance of the Si anode indicates that Al/Alg-TUEG polymer with rapid self-healing capability at room-temperature is one of the promising binder candidates for next-generation high-energy-density lithium-ion batteries.

Thin and Homogenous Surface Functionalization of Lithium Metal Anodes by Defined Molecular Treatment

The safe and stable utilization of lithium metal as an anode in rechargeable batteries is still a major challenge. One way to improve the performance of lithium anodes is the modification of its surface. Here we report two possible methods for lithium surface modification using a combination of tris(N,N-tetramethylene)phosphoric acid triamide and an alcohol for dip coating. The coatings lead to a thin and homogenous surface layer on the electrodes which causes diminished cell resistance and enhanced life time in symmetrical transference cells as well as enhanced capacity retention in Li-S batteries. Surface analyses by XPS and SIMS prove the incorporation of phosphorus and nitrogen into the SEI and the presence of highly lithium ion conductive Li3N.

Theoretical investigations of Ti4C3 and Ti4C3T2 (T = F, O and OH) monolayers as anode materials for Li-ion batteries

Two-dimensional transition metals carbides have gained widespread researching attention as promising alternative anodes for rechargeable batteries due to their high reversible capacity. Herein, we study the electrochemical properties of Ti4C3 monolayer and its functionalized derivatives (Ti4C3T2) in Li-ion batteries by first-principles methods. The Ti4C3 and Ti4C3O2 monolayers show large capacities, able to adsorb two layers of Li on both sides of the monolayer, generating theoretical capacities of 470 and 412 mA·h/g, respectively. The diffusion barriers on bare Ti4C3 monolayer are 19.5 meV, which is lower than most of the 2D materials that have been reported. Finally, we also investigated the impact of intrinsic defects on adsorption and diffusion of Li on Ti4C3 and Ti4C3T2 monolayers. Calculations show that the introduction of carbon vacancies (VC) hinders Li adsorption on Ti4C3 and Ti4C3O2 monolayers but promotes Li adsorption on Ti4C3F2 monolayer. Titanium vacancies (VTi) facilitate the adsorption of Li on the Ti4C3F2 and Ti4C3O2 monolayers. The presence of vacancies also changes the diffusion behavior of Li. This work has a theoretical significance for the design of lithium-ion battery anode materials.

Construction of the Embedded Li4Ti5O12-MWCNTs Nanocomposite Electrode for Diverse Applications in Electrochemical Sensing and Rechargeable Battery

Here, a facile and cost-effective hydrothermal method was used to synthesize lithium titanate (Li4Ti5O12, (LTO))-multiwalled carbon nanotubes (MWCNTs) nanocomposite for the bifunctional property of sensing and energy storage applications. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) were used to confirm the formation of LTO-MWCNTs nanocomposite. The electrochemical sensing of Dopamine (DA) at LTO-MWCNTs modified glassy carbon electrode (GCE) was studied. The modified electrode demonstrated remarkable sensitivity, with a detection limit of 1.54 µM of DA. Moreover, the modified electrode was used for the selective measurement of DA in presence of 5-hydroxytryptamine (5-HT) and folic acid (FA) without interfering with their respective potentials. The modified electrode was used to quantify the DA in commercial DA injection sample with satisfactory recoveries. The modified LTO-MWCNTs/GCE electrode showed acceptable reproducibility and excellent stability. In addition, LTO-MWCNTs nanocomposite electrode delivered a high initial discharge capacity of 176 mAh g− 1 at a charge-discharge rate of 1 C in a constant-current charge-discharge experiment, which proved its efficacy as a rechargeable battery anode material.

Tuning Lithiophilic Sites of Ag-Embedded N-Doped Carbon Hollow Spheres via Intentional Blocking Strategy for Ultrastable Li Metal Anode in Rechargeable Batteries

Tuning Lithiophilic Sites of Ag-Embedded N-Doped Carbon Hollow Spheres via Intentional Blocking Strategy for Ultrastable Li Metal Anode in Rechargeable Batteries

Loss-free pulverization by confining copper oxide inside hierarchical nitrogen-doped carbon nanocages toward superb potassium-ion batteries.

Taking the advantages of hierarchical nitrogen-doped carbon nanocages (hNCNCs) with nanocavities for encapsulation and multiscale micro-meso-macropores/high conductivity for mass/electron synergistic transportation, a conversion-type CuO anode material is confined inside hNCNCs for potassium storage. The so-obtained yolk-shelled CuO@hNCNC hybrids have tunable CuO contents in the range of 11.7-63.7 wt%. The unique architecture leads to the loss-free pulverization of the active components during charge/discharge, which increases the surface-controlled charge storage, shortens the K+ solid diffusion lengths with an enlarged K+ diffusion coefficient, and meanwhile enhances the rate capability and durability. Consequently, the optimized CuO@hNCNC delivers a high specific capacity of 498 mA h g-1 at 0.1 A g-1 and 194 mA h g-1 at 10.0 A g-1 based on the total mass of CuO@hNCNC, and a long-term stability. The capacity based on the CuO active component reaches a record-high 522 mA h g-1 at 1.0 A g-1 after 2000 cycles, which is ca. 2.5 times the state-of-the-art value in the literature. The evolution of the cycling performance with CuO loading is well understood based on the loss-free pulverization. This study demonstrates a new strategy to turn the generally harmful pulverization of active components into a beneficial factor for K+ storage, which paves the way for exploring high-performance anodes for rechargeable batteries.