Low Initial Coulombic Efficiency Research Articles

Analysis of research progress in improving the performance of silicon-based anode materials for lithium-ion batteries: a combination of nanostructured silicon and silicon-based composites

With the development and wide-use of lithium-ion batteries, silicon, due to its high theoretical specific capacity and superior fast charging performance, is being studied intensively and extensively as a new generation of anode materials for the batteries. However, challenges of large volume expansion and poor electrical conductivity has limited the performance and commercial applications of silicon-based anode materials, which is led by pulverization of silicon particles, low initial coulombic efficiency, and unstable solid-electrolyte interphase films. To solve the issues, five main strategies have been proposed correspondingly: nanostructured silicon, silicon-based composites, new binders, new electrolyte additives, and pre-lithiation. Among them, the approaches of nanostructured silicon (0D, 1D, 2D) and silicon-based composites (silicon/carbon, silicon/metal, silicon/transition metal oxide) are practical and effective, thus being explored in depth as the focus of many researches, respectively. After summarizing and analyzing the research progress in enhancing the performance of silicon-based anode materials, it is inferred that the advantages of nanostructured silicon are complementary with those of silicon-based composite materials. Silicon-based nanocomposite materials, as the combination of nanostructured silicon and silicon-based composites, are comparatively more significant and useful than either of those. Therefore, the trend of combining the two strategies to achieve a better improvement is unstoppable.

Interphasial Pre-lithiation and Reinforcement of Micro-Si Anode through Fluorine-free Electrolytes.

Micro-sized silicon (mSi) anodes offer advantages in cost and tap density over nanosized counterparts. However, its practical application still suffers from poor cyclability and low initial and later-cycle coulombic efficiency (CE), caused by the unstable solid electrolyte interphase (SEI) and irreversible lithiation of the surface oxide layer. Herein, a bifunctional fluorine (F)-free electrolyte was designed for the mSi anode to stabilize the interphase and improve the CE. A combined analysis revealed that this electrolyte can chemically pre-lithiate the native oxide layer by the reductive LiBH4 , and relieve SEI formation and accumulation to preserve the internal conductive network. The significance of this F-free electrolyte brings unprecedented F-free interphase that also enables the high-performance mSi electrode (80 wt % mSi), including high specific capacity of 2900 mAh/g, high initial CE of 94.7 % and excellent cyclability capacity retention of 94.3 % after 100 cycles at 0.2 C. This work confirms the feasibility of F-free interphase, thus opening up a new avenue toward cost-advantaged and environmentally friendly electrolytes for more emerging battery systems.

Engineering Ultrathin Carbon Layer on Porous Hard Carbon Boosts Sodium Storage with High Initial Coulombic Efficiency.

Hard carbon (HC) has been widely adopted as the anode material for sodium ion batteries (NIBs). However, it is troubled by a low initial Coulombic efficiency (ICE) due to its porous structure. Herein, a graphitized and ultrathin carbon layer coating on HC is proposed to solve this challenge. The as-prepared porous carbon material coated with an ultrathin carbon layer composite (PCS@V@C) exhibits a cavity structure, which is prepared by using bis(cyclopentadienyl) nickel (CP-Ni) as the carbon source for outer coating, glucose carbon spheres as porous carbon, and introducing a silica layer to facilitate the coating process. When utilized as the anode for NIBs, the material shows an ICE increase from 47.1% to 85.3%, and specific capacity enhancement at 0.1 A g-1 from 155.3 to 216.7 mA h g-1. Moreover, its rate capability and cycling performance are outstanding, demonstrating a capacity of 140.3 mA h g-1 at 10 A g-1, and a retaining capacity of 225.6 mA h g-1 after 300 cycles at 0.1 A g-1 with the Coulombic efficiency of 100% at the second cycle. The excellent electrochemical performance of the PCS@V@C is attributed to the ultrathin carbon layer, which is beneficial for the formation of a stable solid electrolyte interphase (SEI) film. Therefore, this study provides a feasible surface modification method for the preparation of anode materials for NIBs with high specific capacity and ICE.

Deep etching assisted hollow-carbon-skeleton structured porous Co0.85Se nanocubes anchored on MXene nanosheets for superior sodium storage toward ultrahigh initial Coulombic efficiency

Cobalt selenide (CoSex), as a significant member of transition-metal selenides (TMSe), has attracted great interest as anode materials of sodium ion batteries (SIBs), owing to the superior sodium storage capacity. However, the low initial Coulombic efficiency (ICE), inferior rate capability and terrible cycling stability still restrict its practical application. Thus, we develop a method of tannic acid (TA) deep-etching to build up hollow Co metal-organic frameworks (Co-MOF), then combined with MXene nanosheets through the electrostatic self-assembly and meanwhile tailored the solid electrolyte interface (SEI) simultaneously to address above existing problems of CoSex anode. The hollow-carbon-skeleton structured porous Co0.85Se nanocubes anchored on the MXene nanosheets (TA-Co0.85Se-MXene) greatly buffer the huge volume changes, reinforce the structure of the electrode and accelerate the Na+/electron-transport kinetics. Furthermore, an ideal SEI film has been formed by employing the chosen ether-based electrolytes. Owing to the fabricated structure and tailored SEI, the TA-Co0.85Se-MXene anode exhibits ultrahigh ICE of 91 %, superior rate capability of 389 mA h g−1 at 5 A g−1, and outstanding long-term cycling stability of 418 mA h g−1 at 1 A g−1 for 1000 cycles. This work proposes an effective strategy to design transition metal selenides anodes with ultrahigh ICE and superior sodium storage properties.

Recent advances of SiO x -based anodes for sustainable lithium-ion batteries

The world is facing an ever-growing global energy crisis with unprecedented depth and complexity. The sustainable development of high energy density lithium-ion batteries for electric vehicles and portable electric devices has become a feasible way to deal with this problem. Silicon suboxides (SiO_<i>x</i>) have been deemed as one of the most promising anode materials because of their ultrahigh theoretical lithium storage capacity, proper working potential, natural abundance, and environmental friendliness. However, the mass utilization of SiO_<i>x</i>-based anodes is severely obstructed by their low electrical conductivity and inevitable volume expansion. While lithium silicate and lithium oxide formed in the first lithiation process act as buffer layers to some extent, it is urgent to address the accompanying low initial Coulombic efficiency and unsatisfactory cycling stability. In this review, we summarized recent advances in the synthesis methods of SiO_<i>x</i>-based materials. Besides, the benefits and shortcomings of the various methods are briefly concluded. Then, we discussed the effective combination of SiO_<i>x</i> with carbon materials and designs of porous structure, which could considerably enhance the electrochemical performance in detail. Furthermore, progresses on the modified strategies, advanced characteristics and industrial applications for SiO_<i>x</i>-based anodes are also mentioned. Finally, the remaining challenges encountered and future perspectives on SiO_<i>x</i>-based anodes are highlighted.

Revealing the Subzero-Temperature Electrochemical Kinetics Behaviors in Ni-Rich Cathode.

The sluggish kinetics in Ni-rich cathodes at subzero temperatures causes decreased specific capacity and poor rate capability, resulting in slow and unstable charge storage. So far, the driving force of this phenomenon remains a mystery. Herein, with the help of in-situ X-ray diffraction and time of flight secondary ion mass spectrometry techniques, the continuous accumulation of both the cathode electrolyte interphase (CEI) film formation and the incomplete structure evolution during cycling under subzero temperature are proposed. It is presented that excessively uniform and thick CEI film generated at subzero temperatures would block the diffusion of Li+ -ions, resulting in incomplete phase evolution and clear charge potential delay. The incomplete phase evolution throughout the Li+ -ion intercalation/de-intercalation processes would further cause low depth of discharge and poor electrochemical reversibility with low initial Coulombic efficiency, as well. In addition, the formation of the thick and uniform CEI film would also consume Li+ -ions during the charging process. This discovery highlights the effects of the CEI film formation behavior and incomplete phase evolution in restricting electrochemical kinetics under subzero temperatures, which the authors believe would promote the further application of the Ni-rich cathodes.

Mg‐doped, carbon‐coated, and prelithiated SiOx as anode materials with improved initial Coulombic efficiency for lithium‐ion batteries

AbstractSilicon suboxide (SiOx, x ≈ 1) is promising in serving as an anode material for lithium‐ion batteries with high capacity, but it has a low initial Coulombic efficiency (ICE) due to the irreversible formation of lithium silicates during the first cycle. In this work, we modify SiOx by solid‐phase Mg doping reaction using low‐cost Mg powder as a reducing agent. We show that Mg reduces SiO2 in SiOx to Si and forms MgSiO3 or Mg2SiO4. The MgSiO3 or Mg2SiO4 are mainly distributed on the surface of SiOx, which suppresses the irreversible lithium‐ion loss and enhances the ICE of SiOx. However, the formation of MgSiO3 or Mg2SiO4 also sacrifices the capacity of SiOx. Therefore, by controlling the reaction process between Mg and SiOx, we can tune the phase composition, proportion, and morphology of the Mg‐doped SiOx and manipulate the performance. We obtain samples with a capacity of 1226 mAh g–1 and an ICE of 84.12%, which show significant improvement over carbon‐coated SiOx without Mg doping. By the synergistical modification of both Mg doping and prelithiation, the capacity of SiOx is further increased to 1477 mAh g–1 with a minimal compromise in the ICE (83.77%).

Prelithiated SiO x Anode Materials for Fast Chargeable Lithium-Ion Batteries

To meet the increased demands for electric vehicles(EV), Lithium-ion batteries(LIBs) requires fast charging capability. Conventional LIBs using graphite anodes (with a theoretical specific capacity of 372mAh g-1) have limitations with lithium plating and slow kinetics during fast charging process. To overcome these limitations, many anode materials have been explored in the attempt to replace graphite. Among silicon based anode materials, SiO x is one of suitable materials for fast charging due to its high reaction voltage and high energy density. However, its low initial Coulombic efficiency(ICE) and poor cycle life remain as critical challenges. Herein, we propose prelithiated SiO x materials prepared by dehydrogenation-driven prelithiation of SiO x using LiH to improve the low ICE and poor cycle life. The prelithiated SiO x shows about 85.5 % of ICE and improved long-term cycle performance for over 300 cycles. Also, the prelithiated SiO x anode shows higher charged capacity at high current density. More detailed microstructure and electrochemical properties of the prelithiated SiO x materials will be discussed in this presentation.

Topology Optimization of Prelithiated Sio for Improving Dimensional Stability

As the demand for high energy density materials of lithium ion batteries increases, silicon monoxide is considered one of the promising anode materials that can replace the conventional anode materials. However, the low initial Coulombic efficiency(ICE) and the poor cycle stability bottlenecks the commercialization of SiO material. Although numerous efforts have been made, these two chronic issues of SiO have not been solved simultaneously. Here, we demonstrated a prelithiation method to improve the ICE as well as cycle ability by optimizing the topology of prelithiated SiO. Calorimetric method and LA-APT analysis revealed that four exothermic reactions are related with the topology and microstructure of prelithiated SiO. At the optimum heat treatment temperature of 650 ℃, the prelithiated SiO showed a capacity of 1164 mAh g-1 with an ICE of 89.6 % and a remarkable capacity retention of 73.4 % at 300 cycles. We also found that the optimized electrode expanded less compared to non-optimized prelithiated SiO materials. The outstanding electrochemical properties were attributed to the modulated topological arrangement of the active Si phase and Li2SiO3 inactive buffer phase. Further description of the topological optimization will be discussed in the presentation.

Endothermic Dehydrogenation-Driven Preventive Magnesiation of Sio by Magnesium Hydride for High-Performance Sio-Based Lithium Storage Materials

Silicon monoxide (SiO)-based materials have gained much attention as high-capacity lithium storage materials because of their superior cycle performance. However, low initial Coulombic efficiency (ICE) of SiO derived from the irreversible electrochemical reaction of the amorphous SiO2 phase in SiO makes wide use of the SiO-based anode materials in lithium-ion batteries challenging. Magnesiation of SiO is one of the promising solutions to improve ICE of SiO-based anode materials. Here, we propose an endothermic dehydrogenation-driven magnesiation of SiO by employing MgH2 to improve both ICE and cycle performance. The resulting Si/Mg2SiO4 nanocomposite material showed much-improved ICE of 89.5% and long-term cycle performance for over 300 cycles compared to the homologue prepared by the magnesiation of SiO using Mg and pristine SiO. High-resolution transmission electron microscopy with thermogravimetry−differential scanning calorimetry revealed that the endothermic dehydrogenation of MgH2 mitigates the rapid temperature rise during magnesiation of SiO, thereby inhibiting the increase of Si domain size in the resulting Si/Mg2SiO4 nanocomposite. Detailed material characterization and electrochemical analysis of Si/Mg2SiO4 nanocomposite materials will be discussed in this presentation.

Significantly Improving the Initial Coulombic Efficiency of TiO2 Anode for Sodium-Ion Batteries.

Titanium dioxide (TiO2) can serve as a candidate anode material for sodium-ion batteries (SIBs) with the merits of their low cost, abundance, and environment friendliness. However, its low initial Coulombic efficiency (ICE) and sluggish sodium-ion diffusion greatly limit its further practical applications. Herein, we report a one-step prepotassiation strategy to modify commercial TiO2 by a spontaneous chemical reaction using potassium naphthalene (K-Nt). Prepotassiation effectively compensates for the irreversible Na loss and induces a homogeneous, dense, and robust artificial solid electrolyte interphase (SEI) on its surface. The well-distributed artificial SEI suppresses the excessive electrolyte decomposition, contributing to rapid interfacial kinetics and stable Na+ insertion/extraction. Therefore, such modified commercial TiO2 anodes demonstrate significantly improved ICE (72.4%) and outstanding rate performance (176.4 mAh g-1 at 5 A g-1). This simple and efficient method for promoting ICEs and interfacial chemistry also demonstrates universality and practical value for other anodes in SIBs.

Synthesized Fe-doped Co3O4 nanoparticles-based anode for high-performance lithium-ion batteries application

ABSTRACT Co3O4 has been considered a promising anode material because of its high theoretical capacity (890 mAh/g) and remarkable energy density. Unfortunately, it suffers from low initial coulombic efficiency, rapid capacity fading, poor electronic conductivity, large volume changes, and aggregation during the lithium ion intercalation/deintercalation process. In this work, a series of Fe2+-doped Co3O4 nanostructured materials Co3(1-x)Fe3xO4 (x = 0, 0.01, 0.02 and 0.03) were produced by a simple chemical co-precipitation method. The Fe doping led to a slight increase of the lattice parameter, which is beneficial to the rapid diffusion of Li+ ion during the lithiation/delithiation process. Meanwhile, the Fe-doped Co3O4 sample exhibited an excellent rate capability of 886.47 mAh/g at 500 mA/g, and outstanding cyclic stability (1156.91 mAh/g for 50 cycles, with the capacity retention rate of 83.53% at the current density of 100 mA/g), demonstrating improved electrochemical performance, compared with that of pure Co3O4. The good electrochemical performance profited from the formation of oxygen vacancies by Fe doping, which provided more space for Li+ diffusion and improved the electronic conductivity of the anode material. This work provides a simple way to improve the comprehensive electrochemical performance of the transitional metal oxide Co3O4 anode electrodes for lithium-ion batteries.

High-Energy Ball Milling Promoted Sulfur Immobilization for Constructing High-Performance Na-Storage Carbon Anodes.

Sulfur (S) doping is an effective method for constructing high-performance carbon anodes for sodium-ion batteries. However, traditional designs of S-doped carbon often exhibit low initial Coulombic efficiency (ICE), poor rate capability, and impoverished cycle performance, limiting their practical applications. This study proposes an innovative design strategy to fabricate S-doped carbon using sulfonated sugar molecules as precursors via high-energy ball milling. The results show that the high-energy ball milling can immobilize S for sulfonated sugar molecules by modulating the chemical state of S atoms, thereby creating a S-rich carbon framework with a doping level of 15.5 wt %. In addition, the S atoms are present mainly in the form of C-S bonds, facilitating a stable electrochemical reaction; meanwhile, S atoms expand the spacing between carbon layers and contribute sufficient capacitance-type Na-storage sites. Consequently, the S-doped carbon exhibits a large capacity (>600 mAh g-1), a high ICE (>90%), superior cycling stability (490 mAh g-1 after 1100 cycles at 5 A g-1), and outstanding rate performance (420 mAh g-1 at a high current density of 50 A g-1). Such excellent Na-storage properties of S-doped carbon have rarely been reported in the literatures before.

Enhancing the Initial Coulombic Efficiency of Sodium-Ion Batteries via Highly Active Na2 S as Presodiation Additive.

Recently, sodium-ion batteries (SIBs) have received considerable attention for large-scale energy storage applications. However, the low initial Coulombic efficiency of traditional SIBs severely impedes their further development. Here, a highly active Na2 S-based composite is employed as a self-sacrificial additive for sodium compensation in SIBs. The in situ synthesized Na2 S is wrapped in a carbon matrix with nanoscale particle size and good electrical conductivity, which helps it to achieve a significantly enhanced electrochemical activity as compare to commercial Na2 S. As a highly efficient presodiation additive, the proposed Na2 S/C composite can reach an initial charge capacity of 407mAhg-1 . When 10wt.% Na2 S/C additive is dispersed in the Na3 V2 (PO4 )3 cathode, and combined with a hard carbon anode, the full cell achieves 24.3% higher first discharge capacity, which corresponds to a 18.3% increase in the energy density from 117.2 to 138.6Whkg-1 . Meanwhile, it is found that the Na2 S additive does not generate additional gas during the initial charging process, and under an appropriate content, its reaction product has no adverse impact on the cycling stability and rate performance of SIBs. Overall, this work establishes Na2 S as a highly effective additive for the construction of advanced high-energy-density SIBs.

Recent Progress on Electrolyte Boosting Initial Coulombic Efficiency in Lithium‐Ion Batteries

AbstractThe initial Coulombic efficiency (ICE) of electrode materials is closely related to the energy density of lithium‐ion batteries (LIBs). However, some promising electrode materials for next generation LIBs suffer from low ICE, which inevitably hinders their practical application. Among the discovered modified strategies for LIBs, electrolyte optimization has attracted extensive attention due to its facile operation process. Herein, the role of ICE in LIBs is first analyzed. Subsequently, the recent progress on effective electrolyte optimization strategies for boosting ICE in LIB is summarized (including the optimization of lithium salt, salt concentration, solvent, and electrolyte additive). Finally, future research directions of electrolyte optimization for boosting ICE are proposed. This review provides valuable guidance for developing advanced electrolyte for LIBs.

Imitating Architectural Mortise-Tenon Structure for Stable Ni-Rich Layered Cathodes.

Ni-rich layered oxides are the most promising cathodes for Li-ion batteries, but chemo-mechanical failures during cycling and large first-cycle capacity loss hinder their applications in high-energy batteries. Herein, by introducing spinel-like mortise-tenon structures into the layered phase of LiNi0.8 Co0.1 Mn0.1 O2 (NCM811), the adverse volume variations in cathode materials can be significantly suppressed. Meanwhile, these mortise-tenon structures play the role of the expressway for fast lithium-ion transport, which is substantiated by experiments and calculations. Moreover, the particles with mortise-tenon structures usually terminate with the most stable (003) facet. The new cathode exhibits a discharge capacity of 215mAhg-1 at 0.1C with an initial Coulombic efficiency of 97.5%, and capacity retention of 82.2% after 1200 cycles at 1C. This work offers a viable lattice engineering to address the stability and low initial Coulombic efficiency of the Ni-rich layered oxides, and facilitates the implementation of Li-ion batteries with high-energy density and long durability.

3D Carbon Coating Enabled High‐capacity and Stable Micro‐sized Silicon Suboxide‐graphite Blended Anodes for Practical Lithium‐ion Batteries

AbstractSilicon oxide (SiOx) is a promising anode candidate of lithium‐ion batteries (LIBs) owing to its extremely high specific capacity. However, the low initial Coulombic efficiency (ICE) and rapid capacity degradation of SiOx, triggered by the enormous volume variation upon repeated (de)lithiation, gravely hinder its practical use. Herein, two mass‐produced micro‐sized SiOx@C composites with obviously different morphologies for commercial LIBs are reported. Particularly, the SiOx‐graphite blended anode (SiOx@3D‐G‐Gr) based on SiOx wrapped by three‐dimensional (3D) carbon layers (SiOx@3D‐G) exhibits a capacity of 519 mAh g−1, an ICE of 90.0 % and a capacity retention of 83.4 % at 0.2 C over 100 cycles. which is far exceeding its counterpart SiOx@C‐H‐Gr (65.7 %). The obtained impressive properties of SiOx@3D‐G originate from the critical contribution of 3D carbon layers, which serves as the effective stress buffer and protective layer as well as the strong networks for electron/Li+ transport. Accordingly, the full‐cell based on SiOx@3D‐G‐Gr anode and commercial LiCoO2 cathode delivers a capacity of 803 mAh and an excellent capacity retention of 95.6 % (616 mAh, 96.6 % for graphite, respectively) at 1 C over 100 cycles with a stabilized CE of nearly 100 %. The micro‐sized SiOx@3D‐G showing a promising prospect in the commercial‐grade anodes in LIBs.

A bimetallic induced enhanced 3D electron transport network supported by micro constrain area of balls-in-ball structure used for high performance sodium storage

Metal selenides' reversible capacity and rate performance are greatly constrained by their low intrinsic conductivity, severe volume expansion, and low initial coulombic efficiency, therefore selenides with high theoretical capacities cannot be employed as efficient anode for sodium ions batteries. Here, we report a simple and feasible methodology for synthesizing (M−Mn)Se/C (M = Co, Ni) heterogeneous anode materials based on Kirkendall diffusion process. A heterogeneous balls-in-ball structure is created when the nanospheres are concentrated in a microsphere. The confinement effect of the nano-scale enables each microsphere to act an effective reaction micro-region. The transport of sodium ions is constrained more by electrons when the electrode material reaches the nanoscale. In terms of composition and structure, the balls-in-ball structure with heterogeneous composition greatly promotes the electron transfer. The bimetal-regulated heterogeneous (M−Mn)Se/C electrode exhibits bonding energy changed under the synergistic effect between the two metal metals, thus forming significant quantity of built-in electric field to promote electron transport. The amount of MnSe is distributed uniformly around each MSe in every single micro-sphere. The built-in electric field establish an efficient 3D electron transport network, thus making the optimization in composition substantially boosted by a sensible structural design. (M−Mn)Se/C showed excellent sodium storage performance through the cooperative optimization of composition and structure. To our expectation, (CoMn)Se/C delivered a high reversible capacity (597 mAh·g−1 at 100 mA⋅g−1) and enduring cyclic stability (retention rate of 97.8% after 2000 cycles at 5000 mA⋅g−1). In addition, a full cell assembled by Na3V2(PO4)3 showed a high capacity of 350 mAh/g and a ultra-high energy density of 162.2Wh/kg. This work provides a simple method for constructing the anode electrode of high-performance sodium ions batteries.

Boosting the electrochemical performance of Li-rich Mn-based cathode materials via oxygen vacancy and spinel phase integration

Li-rich Mn-based oxide cathodes (LMOs) are regarded as one of the most prospective high energy density cathodes due to the reversible anion redox reaction, which gives them a very high capacity. However, LMOs materials usually have problems like low initial coulombic efficiency (ICE) and poor cycling performance during cycling, which are associated with irreversible surface O2 release and unfavourable electrode/electrolyte interface side reactions. Herein, an innovative and scalable NH4Cl-assisted gas–solid interfacial reaction treatment technique is employed to construct oxygen vacancies and spinel/layered heterostructures simultaneously on the surface of LMOs. The synergistic effect of the oxygen vacancy and the surface spinel phase can not only effectively enhance the redox properties of the oxygen anion and inhibit irreversible oxygen release, but also effectively mitigate the side reactions at the electrode/electrolyte interface, inhibit the formation of CEI films and stabilize the layered structure. The electrochemical performance of the treated NC-10 sample improved significantly, showing an increase in ICE from 77.4 % to 94.3 % and excellent rate capability and cycling stability, with a capacity retention of 77.9 % after 400 cycles at 1 C. This oxygen vacancy and spinel phase integration strategy offers an exciting prospect and avenue for improving the integrated electrochemical performance of LMOs.

Chemical prepotassiation enabling high-efficiency and long-life alloy anodes for potassium-ion batteries

Using high-capacity alloy anodes can grandly advance potassium-ion batteries. However, one common issue plaguing these anodes is the loss of active K+ ions associated with persistent side reactions on unstable electrode-electrolyte interfaces, resulting in low initial Coulombic efficiency (ICE) and shortened cycling life. Herein, we first explore the potential of a solution-based potassiation reagent (potassium-biphenyl in dimethoxyethane, K-Bp/DME) for chemical prepotassiation. With a low redox potential of 0.45 V vs. K+/K, the K-Bp/DME solution can readily pre-storing K+ ions into various alloy-type anodes by a simple immersion operation in a few minutes. Taking nanostructured Bi/P/CNT composite as an example, we demonstrate that the K-Bp/DME prepotassiation simultaneously enables the notable ICE improvement (from 51.9% to 96.2%) and long-life cycling (running 700 cycles at 1.5 A g−1 with a tiny capacity attenuation rate of 0.031% per cycle) by forming a KF-rich SEI film. Furthermore, the full cell assembled by coupling the prepotassiated Bi/P/CNT anode with a potassium Prussian blue cathode delivers a desirable ICE of 88.6% and superior capacity retention of 75.3% after 450 cycles at 0.3 A g−1. Besides, this prepotassiation method is also successfully extended to other anodes (Sb and Sn), indicating its general applicability.