Lithium-ion Capacitors Research Articles

Conductive Modification of Activated Carbon Fiber Cloths via Electrophoretic Deposition for Cathode in Lithium‐Ion Capacitor

AbstractWith the growing demand for high performance energy storage devices, the advanced manufacturing technology of electrodes, which is a crucial component, has become increasingly essential in academic research and industrial applications. Activated carbon fiber cloth (ACFC) is a promising candidate for lithium‐ion capacitor (LIC) electrodes due to its abundant internal space and pores. However, the wider application of ACFC is restricted by its inferior conductivity. The conventional coating process is costly in terms of both materials and time and is only applicable to surface treatment with limitations in treating shaped substrate such as ACFCs. To overcome the applications obstacles of ACFC in batteries and capacitors, we propose a novel strategy for modification that utilizes electrophoretic deposition (EPD) to deposit Super P onto the surface, thus enhancing its conductivity. After being deposited for 10 min at 80 V, the modified ACFC exhibited higher conductivity. When matched with Si@C anode, the assembled LIC demonstrates excellent initial specific areal capacitance (710 mF cm−2) and cycling retention, with 76.92% remaining after 100 cycles at a current density of 7 mA cm−2. When matched with Si@C anode, the assembled LIC demonstrates excellent initial specific areal capacitance (26.91 F g−1) and cycling retention, with 85.21% remaining after 100 cycles at a current density of 0.2 A g−1. This work showcases the potential of EPD technology in the realm of electrode preparation and offers insights for electrode manufacture in other systems.

Flexible and free-standing MXene decorated biomass-derived carbon cloth membrane anodes for superior lithium-ion capacitors

Two-dimensional transition metal materials, MXenes, have attracted tremendous attention in energy storage applications due to their layered structure, good electrical conductivity, and abundant functional groups. In this work, Ti3C2Tx MXene nanosheets and carbon nanotubes (CNTs) were uniformly sprayed and successfully loaded on the cotton nonwoven fabric-derived carbon cloth (CC) substrate by electrostatic self-assembly. The as-prepared flexible MXene-CNTs-CC membrane electrodes with enlarged interlayer spacing and high conductivity fabric support exhibited excellent electrochemical performance. In terms of lithium-ion batteries, the optimized MXene-CNTs-CC anode delivered an ultrahigh initial discharge capacity of 2277.5 mAh g−1 at 0.1 A g−1 along with notable cyclability (1149.8 mAh g−1 after 100 cycles) and rate capability (544.1 mAh g−1 after 200 cycles at 2 A g−1) in half cells. The full cells assembled with LiCoO2 cathode also displayed good cycling stability with a high reversible discharge capacity of 833.5 mAh g−1 after 100 cycles at 0.1 A g−1. Remarkably, the further constructed lithium-ion capacitors with the designed porous carbon nanofiber cathode could maintain energy densities of 121.5 to 20.8 Wh kg−1 with the corresponding power densities of 125 to 12,500 W kg−1, and achieved capacitance retention of 76.3 % after 10,000 cycles at 1 A g−1, demonstrating excellent long-term cycle durability.

Eliminating the crystal water in hydrated iron fluoride towards fast and high Li-ion storage capacity with ultralong cycling stability

Fluorides as conversion electrodes show great promise for Li-ion batteries due to their high theoretical capacity. However, their use is limited by low electronic conductivity and slow reaction kinetics. Additionally, fluorides usually contain crystal water in their structure, and the impact of this water on their performance is not well understood. Herein, we created FeF3@CNF nanofibers using simple electrospinning and fluorination processes as a potential anode for Li-ion batteries. These nanofibers, with FeF3 nanoparticles (∼50 nm) embeded in carbon, provide efficient pathways for lithium ion transport. By comparing the performance of FeF3 with and without crystal water through theoretical calculations and kinetics analysis, we found that removing the crystal water improves reaction kinetics and reduces mechanical strain, resulting in a significantly higher specific capacity, faster kinetics, and excellent cycling stability. In/ex-situ analytical techniques demonstrate that the rapid Li+ storage in the FeF3@CNF anode is due to a reversible conversion mechanism and particle refinement during cycling. The FeF3@CNF anode shows a kinetic advantage that matches well with activated carbon cathode, leading to superior cycling stability. This work highlights the crucial role of removing crystal water in optimizing fluoride-based electrodes and offers new insights for developing high-performance fluoride-based anodes for lithium-ion capacitors.

Harnessing Free-Standing Flexible Dual Carbon Lithium-Ion Capacitors with Carbon Fiber–Pitch Composite Electrodes

Harnessing Free-Standing Flexible Dual Carbon Lithium-Ion Capacitors with Carbon Fiber–Pitch Composite Electrodes

A simple formula to fabricate high performance lithium metal capacitors

Energy storage technologies that are low-cost, with long cyclability, high rate-capability as well as high energy and power densities are under intensive investigation for sustainable clean energy transition. In this paper, we report a high-performance lithium metal capacitor (LMC) achieved by a simple slurry modification during the cathode film preparation. We show that a mere substitution of ~0.4 wt% conductive carbon by single walled carbon nanotubes (SWCNTs) increased the specific energy of LMCs by 22 %. Porous carbon cathode in this study was obtained from a non-edible biomass (coconut rachis); the optimized sample showed desirable surface characteristics (surface area ~1933 m2⸱g−1 and pore diameter ~2.0 nm) as well as high edge-plane fraction (ratio between relative density of edge and basal plane ~0.4). Cathode with no SWCNTs show a specific capacitance (CS) of ~133 F·g−1@0.1 A·g−1 in the potential window 2.0–4.0 V in the Li//LiPF6//AC device configuration. Removal of conductive carbon by SWCNTs up to ~0.6 wt% increased electrical conductivity of the cathode; however, the charge storability enhancements were only up to ~0.4 wt%. The optimum device delivered a CS ~188 F·g−1@100 mA·g−1 in the potential window 2.0–4.0 V with improved rate capability and cycling stability. Electrochemical impedance spectroscopy was used as a tool to understand the charge kinetics at the electrode; these studies collectively validated the observed enhancements in the charge storability. The device hereby developed showed superior specific capacity than most of the reported lithium-ion capacitors and comparable to some of the LMBs. The perceived 22 % increase in the specific energy by a mere 0.4 wt% SWCNT substitution is a step forward in fabricating the high-performance LMCs in addition to support the sustainability agenda through the carbon-negative precursors.

Self-Templating Synthesis of Mesoporous Carbon Cathode Materials for High-Performance Lithium-Ion Capacitors.

Lithium-ion capacitors (LICs) have attracted considerable interest because of their excellent power and energy densities. However, the development of LICs is limited by the low capacity of the cathode and the kinetics mismatch between the cathode and anode. In this work, mesoporous carbon materials (MCs) with uniform pore sizes were prepared using magnesium citrate as the raw material through a self-templating method. During the carbonization process, MgO nanoparticles generated from magnesium citrate act as a template, resulting in a more orderly pore structure. The resultant MCs demonstrate a high specific surface area of 1673 m2 g-1 and an abundance of small mesopores, which significantly accelerated ion migration within the electrolyte and expedited the formation of electric double layers. Benefiting from these advantages, the MCs cathode demonstrates a high reversible specific capacity, excellent cycling stability, and rate performance. The assembled MCs-based LIC provides a high energy density of 152.2 Wh kg-1 and a high power density of 14.3 kW kg-1. After 5000 cycles, a capacity retention rate of 80 % at the current density of 1 A g-1 is obtained. These results highlight the excellent potential of MCs as a cathode material for LICs.

Application of prelithiated nanoporous carbon anode for high-power lithium-ion capacitor

Abstract Prelithiated nanoporous carbons were applied as an anode material in lithium-ion capacitors to achieve high-power performance. Nanoporous carbon anodes with different pore structures, graphitization degrees, and prelithiation conditions were comparatively investigated for their rate performance, self-discharge property, and full-cell performance. Prelithiated nanoporous carbon anode prepared under optimized condition exhibited high power and energy densities.

Dual storage mechanism of Bi2O3/Co3O4/MWCNT composite as an anode for lithium-ion battery and lithium-ion capacitor

Bismuth oxide(Bi2O3) and cobalt oxide(Co3O4) are promising owing to their unique properties, high storage capacity, low cost, and eco-friendliness, making them ideal for lithium-ion batteries(LIBs) and lithium-ion capacitors(LICs) anodes. This study presents the synthesis and thorough characterization of Bi2O3/Co3O4 and Bi2O3/Co3O4/MWCNT composites as potential LIB and LIC anode materials. The materials are synthesized using a hydrothermal process succeeded by annealing. Structural, morphological, and compositional studies were analyzed. Various tests evaluated electrochemical performance, including cyclic voltammetry(CV), confirming a dual storage mechanism like alloying and conversion reaction involved for better energy storage. Specific discharge capacities of 834 mAh/g and 1184 mAh/g were recorded for Bi2O3/Co3O4 and Bi2O3/Co3O4/MWCNT composite electrodes at a current density of 100 mA/g, respectively. The composite material exhibited notably enhanced rate capability, with 31 % and 51 % discharge capacities for Bi2O3/Co3O4 and Bi2O3/Co3O4/MWCNT, respectively. The cyclic stability assessment revealed that Bi2O3/Co3O4 and Bi2O3/Co3O4/MWCNT maintained a high coulombic efficiency of around 99 % over 250 charge–discharge cycles at a high current density of 1 A/g. The capacity retention was approximately 253 mAh/g for Bi2O3/Co3O4 and 439 mAh/g for the Bi2O3/Co3O4/MWCNT composite, indicating excellent cyclic stability and minimal energy loss during cycling. Moreover, the LICs assembly of Bi2O3/Co3O4/MWCNT//CB was investigated, revealing a power density of 200 W kg−1 alongside an energy density of 8.64 Wh kg−1. The cyclic stability assessment over 10,000 cycles exhibits a capacity retention of approximately 45 % under a high current density of 2 A/g.

Metal organic framework derived heteroatom doped porous carbon nanocubes enable efficient charge storage in a lithium-ion capacitor

Lithium-ion capacitors (LICs) are regarded as one of the promising technologies towards realizing energy & power dense energy storage systems. However, their energy densities at higher power densities are still limited due to the discrepancy between electrode kinetics of capacitor-like cathode and battery-like anode. Developing carbon materials with well-defined structures, porosity to match the chemical kinetics between electrodes are the major challenges to overcome. In the present work, we have devised a strategy to fabricate S, N dual-doped porous carbon nanocubes (S, N-PCNs) using zeolitic imidazole framework (ZIF)-8 precursors, and employed the PCNs as anode material in LICs. With its well-defined structure, hierarchical porous nature, and abundant heteroatom presence (1.9 % S, 16.2 % N), the pre-lithiated S, N-PCNs based anode has offered a greatly improved reversible storage capacity of ∼930 mAh g−1 at 0.1 A g−1 along with an impressive rate capability and cycling life. When S, N-PCNs anode is paired with activated carbon cathode, the 4 V dual-carbon LIC yields an energy density as high as 120.24 Wh kg−1 and 10.2 kW kg−1 of power density with a good cycle stability of 90.6 % after 5000 charge-discharge cycles. This work would open new scopes of exploring metal-organic framework derived heteroatom-doped porous carbons to make metal-ion capacitors more efficient.

Enhanced pseudocapacitive Li+ charge storage on lithium-rich disordered rock salt vanadium oxide nanocrystalline

Cation disordered rock-salt (DRS) metal compounds, featuring a three-dimensional percolation network for Li+ transportation, have attracted extensive attention as novel anode candidates for high-power lithium-ion batteries (LIBs) and capacitors (LICs). However, their low capacity and poor conductivity remain bottlenecks for their wide-scale usage, especially for high-energy applications. Here, we report a nanocrystal DRS Li3V2O5 (a-DRS-LVO) achieved by an electrochemically induced transformation on amorphous V2O5. The nanocrystalline phase of a-DRS-LVO can provide large active sites for Li+, leading to a surface-controlled solid-state Li+ diffusion behavior. In particular, the specific capacity for a-DRS-LVO reaches 716.8mAh g−1 at 0.1 A/g, exceeding that of DRS-LVO achieved by electrochemically induced transformation on well-crystallized V2O5. Further, a-DRS-LVO can work stably over 1,200 charge–discharge cycles with negligible capacity decay, due to the highly structural integrity stability, no phase change and limited volume change (∼8.2 %). A LIC with this a-DRS-LVO anode yields both high energy density (183 Wh kg−1) and power density (50,000 W kg−1), which are much higher than that of the state-of-art LICs based on graphite and other pseudocapacitive anodes, such as niobium and titanium oxides.

Two-dimensional vanadium carbide (V2C) MXene derived heterostructures for high-performance lithium storage

Li3VO4 is notable for its high theoretical capacity and favorable lithium-ion insertion potential, making it a promising candidate for lithium storage applications. However, its practical use is limited by low electronic conductivity, which results in reduced electrochemical performance and significant resistance polarization during lithium storage. Herein, we developed a Li3VO4/V2CTx heterostructure using a MXene-derived approach, where Li3VO4 is anchored onto a conductive V2CTx MXene substrate. Theoretical calculations suggest that the heterostructure exhibits enhanced lithium adsorption capabilities compared to V2CTx, indicating improved interactions with lithium ions. The synthesized Li3VO4/V2CTx heterostructure demonstrates excellent rate performance and cycling stability. Additionally, a lithium-ion capacitor utilizing this heterostructure as the anode and activated carbon as the cathode achieves impressive power density and energy density. This study underscores the potential of this heterostructure as a high-performance anode material and offers valuable insights for the design of other advanced electrode materials.

Structural regulation of 1T-MoS2/Graphene composite materials for high-performance lithium-ion capacitors

Heterogeneous composite structures are considered an effective strategy by utilizing the advantages of heterogeneous components. However, the relationship between structural modifications and electrochemical performance remains inadequately understood. In this study, we leveraged DFT calculations to elucidate the key advantages of the 1T-MoS2/Gr heterostructure, including its exceptional electrical conductivity, enhanced Li+ adsorption capabilities, and improved Li+ diffusion kinetics. To synthesize the 1T-MoS2/Gr composite, we developed a facile, one-step hydrothermal method using glucose as a reducing agent, achieving an optimal heterostructure that maximized the synergistic properties of the components. By comparing different levels of graphene content, the relationship between structural regulation and electrochemical performance has been studied, and a remarkably significant heterostructure composite material (1T-MoS2/Gr-0.8) was identified. As the anode material for lithium-ion batteries (LIBs), 1T-MoS2/Gr-0.8 presents excellent cycle performance with 467 mAh g−1 under the condition (0.5 A g−1, 600 cycles). Simultaneously, when assembling the lithium-ion capacitor (LIC) device with an activated carbon (AC) cathode, even at a high power density of 11.7 kW kg−1, the energy density of the 1T-MoS2/Gr-0.8//AC LIC is as high as 137.0 Wh kg−1. Moreover, the capacity retention rate remains at 89.9 % even after 2000 cycles at 2 A g−1, demonstrating its candidacy as a high-performance anode material for LICs.

Turn the dust into glory: Hierarchical porous carbon cubes derived from waste tire pyrolysis oil exhibits high capability in symmetric capacitors

Fabricating suitable porous carbon materials that are simultaneously applied in various electrochemical energy storage (EES) systems including supercapacitors (SCs) and lithium-ion capacitors (LICs) has an important significance in meeting the increasing demands in high energy density, high power density along with ultra-long life. Herein, cubic hierarchical porous carbon (CHPC) with abundant micro-mesoporous structures and moderate S, N co-doped atoms has been rationally designed by using MgO cubes as the templates and waste tire pyrolysis oil (WTPO) as carbon source and dopant. Attributed to the unique microstructures, the CHPC materials have been successfully utilized in different EES systems. In the aqueous electrolyte system, the assembled CHPC-2//CHPC-2 with 2 mg cm−2 delivered high specific capacitance of 199.0 at 1 A/g, along with 98.5 % capacity retention rate for 20,000 cycles at 6 A/g. Even at high mass loading of 12 mg cm−2, CHPC-12//CHPC-12 still can deliver high gravimetric and areal capacitances of 187.0 F g−1 and 2.24 F cm−2 at 10 A/g, showing an excellent high-loading performance. Even under extreme conditions of −40 and 60 °C, the assembled SCs still can deliver an ultrahigh capacity retention rate of 97.9 % and 100 % at 10 A/g for 2000 and 8000 cycles, respectively. In addition, the symmetric CHPC//CHPC LICs also have been assembled and displayed a maximal energy density of 133.5 Wh Kg−1 at 1178.2 W Kg−1. This work provides new insight into the high-value utilization of WTPO for prepared porous carbon with excellent electrochemical performance in various EES systems.

Advanced Biocoal Carbon Materials from Biorefinery for both Supercapacitors and Lithium-Ion Capacitor Applications

Advanced Biocoal Carbon Materials from Biorefinery for both Supercapacitors and Lithium-Ion Capacitor Applications

Selection of high rate capability and cycling stability MnO anode material for lithium-ion capacitors: Effect of the carbon source

The N-doped carbon modified MnO composites were successfully prepared using K2MnO4 as the manganese source, CH4N2O as the nitrogen source, and glucose, sucrose, or reduced graphene oxide as the carbon sources. Among them, the composite (MPN) prepared using glucose as the carbon source exhibited excellent electrochemical performance, attributed to its relatively small particle size (6.4 nm), high specific surface area of 199.4 m2·g−1, and a high ID/IG ratio of 0.86. The MnO in MPN contained a significant amount of Mn3+, ∼16.8 %, which is ascribed to the incomplete reduction of high valence Mn during the process of synthesis. With the formation of Mn3+, a large number of cationic vacancies were generated, which increased the diffusion coefficient of Li+ from 2.12 × 10−14 cm2 s −1 to 5.94 × 10−13 cm2 s−1. The carbon layer with appropriate thickness, doped N and mesoporous structure suitable for electrolyte transport provide a fast ion/electron transport channels for MnO, and ensure a stable interface structure in the electrochemical reactions. Consequently, the MPN anode material exhibited remarkable high current discharge capacity (769.5 mAh·g−1 at a high current density of 2 A·g−1) and excellent cycling performance (882.2 mAh·g−1 after 200 cycles at 1 A·g−1), indicating its exceptional rate performance and cycle stability. Furthermore, the lithium ion capacitor constructed with MPN as anode and activated carbon as cathode demonstrated a high specific energy of 190 Wh·kg−1, a high specific power of 205.3 W·kg−1, and an impressive cycling lifespan of up to 3000 cycles without obvious degradation.

Facile synthesis of hollow Zn-Co-S and Zn-Co-P nanostructures supported on Ti3C2Tx MXene nanosheets for high-performance lithium-ion capacitors

Lithium-ion capacitors (LICs) represent a novel energy storage solution, merging the high energy storage capacity of lithium-ion batteries with the adequate power density of supercapacitors. However, the electrochemical performance of lithium-ion capacitors is notably constrained by the inherent imbalance between the charge storage mechanisms and electrochemical reaction dynamics of their anodes and cathodes. In this study, a dual-shell hollow structured ZnCo2S4 was prepared via a two-step hydrothermal method and compared with spherical ZnCo2P4 prepared by calcination. Subsequently, they were respectively anchored onto two-dimensional Ti3C2Tx nanosheets, which possess abundant surface functional groups, through electrostatic adsorption, forming layered semi-encapsulated framework structures. The introduction of MXene significantly enhances the conductivity of the material, restricts the expansion of ZnCo2S4 and ZnCo2P4 during the Li+ insertion/extraction process, and inhibits their aggregation. Under a three-electrode configuration, ZnCo2S4/Ti3C2Tx exhibits excellent rate performance (1004 C·g−1 at 10 A·g−1) and cycling stability (95 % capacity retention after 5000 cycles at 2 A·g−1). The discharge capacity of the ZnCo2S4/Ti3C2Tx LIB is up to 1360 mAh·g−1 at 0.1 A·g−1, and the discharge capacity of the ZnCo2P4/Ti3C2Tx LIB is 1121 mAh·g−1 at 0.1 A·g−1. As an anode material for LIC, ZnCo2S4/Ti3C2Tx demonstrates excellent specific capacitance and rate performance (105 F·g−1 at 0.5 A·g−1). At a power density of 337.10 W·kg−1, ZnCo2S4/Ti3C2Tx//AC LIC exhibits a significant energy density of 136.25 Wh·kg−1. At a current density of 2 A·g−1, ZnCo2S4/Ti3C2Tx//AC LIC retains 89 % of its capacity after 5000 charge-discharge cycles, demonstrating excellent stability for practical applications. ZnCo2P4/Ti3C2Tx//AC LIC exhibits an energy density of 45.20 Wh·kg−1 at a power density of 623.07 W·kg−1, and after 5000 cycles at 2 A·g−1, its capacity retention rate reaches 80 %. These findings suggest that ZnCo2S4/Ti3C2Tx and ZnCo2P4/Ti3C2Tx composites are promising anode materials for LICs.

Thermal Safety Characteristic Analysis of Large‐Format Pouch Li‐Ion Capacitors

Lithium‐ion capacitors (LICs), as the next generation of supercapacitors, combine the high power density and long cycle life of supercapacitors with the high energy density of lithium‐ion batteries, presenting broad prospects for applications and becoming a focal point of research in academia and industry. Safety concerns regarding LICs, particularly the crucial issue of thermal safety, have garnered widespread attention. This study investigates the thermal abuse, electrical abuse, and mechanical abuse of 1100 F LICs, including overheating, overcharging, overdischarging, needling, extrusion, and short circuit tests, with real‐time monitoring of temperature, gas emissions, and voltage to explore thermal runaway mechanisms. The results demonstrate that LICs remain safe under abusive conditions, with no occurrences of fire or explosion hazards.

Fully Conjugated Covalent Triazine Framework Integrating Hexaazatrinaphthylene Unit as Anode Material for High-Performance Hybrid Lithium-Ion Capacitors.

As a high-performance energy storage device consisting of a battery-type anode and a capacitor-type cathode, hybrid lithium-ion capacitors (HLICs) combine the advantages of high energy density of batteries and high power density of capacitors. However, the imbalance in electrochemical kinetics between the battery-type anode and the capacitor-type cathode hinders the further development of HLICs. Fully conjugated covalent organic frameworks have great potential as electrode materials for HLICs due to the designability of their structure. Herein, a fully conjugated covalent triazine framework (PT-CTF) integrating the hexaazatrinaphthylene unit was constructed, which provides abundant active sites (C═N and C═C groups) as the pseudocapacitive anode material for HLICs. And the connection of the triazine unit of PT-CTF improves the molecular conjugate degree, facilitating the transport of electrons. The fabricated PT-CTF||AC HLICs exhibit a high energy density (164.9 Wh kg-1 at 100 mA g-1), large power density (13.1 kW kg-1 at 4 A g-1), and excellent cycling capability (72% after 10 000 cycles at 2 A g-1).

Operando tracking of ion population changes in the EDL electrode of a lithium-ion capacitor during its charge/discharge

This study elucidates in-pore ion population changes in an activated carbon (AC)-based electrode operating within an extended potential range, akin to the positive electrode of a lithium-ion capacitor (LIC). Molecular dynamics (MD) simulations applied to a battery-type electrolyte (1 mol L−1 LiPF6 in EC:DMC), both in bulk and adsorbed within a model porous carbon, reveal partial solvation of Li⁺ cations within the pores and complete desolvation of PF6⁻ anions in both states. Operando electrochemical dilatometry (ECD), in situ potentiostatic electrochemical impedance spectroscopy, and operando Raman spectroscopy on AC electrodes confirm: (i) ionic exchange followed by anion adsorption during initial hole injection from the point of zero charge (PZC) to 4.5 V vs. Li/Li⁺; (ii) desorption and peak liberation of trapped PF6⁻ at 3.2 V vs. Li/Li⁺ during hole withdrawal; (iii) perm-selective adsorption of partially solvated Li⁺ during electron injection down to 2.2 V vs. Li/Li⁺; (iv) cation desorption during electron withdrawal up to PZC followed by similar ionic exchange and anion adsorption (as described in (i)) at potentials above the PZC, however with peak liberation of trapped Li⁺ at 3.8 V vs. Li/Li⁺. The high polarization required to extract trapped ions from the pores may explain the reduced lifespan of LICs, requiring further work to eliminate trapping by optimizing porous texture.

Honeycomb-like N-Doped Carbon Matrix-Encapsulated Co1−xS/Co(PO3)2 Heterostructures for Advanced Lithium-Ion Capacitors

Lithium-ion capacitors (LICs) are emerging as promising hybrid energy storage devices that combine the high energy densities of lithium-ion batteries (LIBs) with high power densities of supercapacitors (SCs). Nevertheless, the development of LICs is hindered by the kinetic imbalances between battery-type anodes and capacitor-type cathodes. To address this issue, honeycomb-like N-doped carbon matrices encapsulating Co1−xS/Co(PO3)2 heterostructures were prepared using a simple chemical blowing-vulcanization process followed by phosphorylation treatment (Co1−xS/Co(PO3)2@NC). The Co1−xS/Co(PO3)2@NC features a unique heterostructure engineered within carbon honeycomb structures, which efficiently promotes charge transfer at the interfaces, alleviates the volume expansion of Co-based materials, and accelerates reaction kinetics. The optimal Co1−xS/Co(PO3)2@NC composite demonstrates a stable reversible capacity of 371.8 mAh g−1 after 800 cycles at 1 A g−1, and exhibits an excellent rate performance of 242.9 mAh g−1 even at 8 A g−1, alongside enhanced pseudocapacitive behavior. The assembled Co1−xS/Co(PO3)2@NC//AC LIC delivers a high energy density of 90.47 Wh kg−1 (at 26.28 W kg−1), a high power density of 504.94 W kg−1 (at 38.31 Wh kg−1), and a remarkable cyclic stablitiy of 86.3% retention after 5000 cycles. This research is expected to provide valuable insights into the design of conversion-type electrode materials for future energy storage applications.