Developing high-performance solid-state electrolytes with both fast Li* transport and stable interfaces remains a critical challenge for next-generation batteries. Herein, we report an innovative molecularlevel interfacial engineering strategy by covalently grafting amino-silane [3-(2-Aminoethylamino)pro pyl]trimethoxysilane (AEAPTMS) onto the surface of Li1.4Al0.2Ti1.8Si0.2P2.8O12 (LATSP) ceramic fillers within polyethylene oxide (PEO)-based composite solid-state electrolytes. Specifically, AEAPTMS not only alleviates filler agglomeration and reduces PEO crystallinity, but also provides unique interfacial functions. The -NH2 groups strongly anchor TFSI-anions via hydrogen-bonding interactions, while the weak coordination between Li* and AEAPTMS reduces the migration energy barrier, thereby regulating the Li* coordination environment and enabling accelerated interfacial Li* transport. Moreover, the engineered interface induces the formation of astable, LiF-rich SEI to suppress side reactions and enhance interfacial stability. Consequently, the optimized PEO-LATSP@AEAPTMS composite electrolyte exhibits superior electrochemical performance, including high ionic conductivity of 8.47 & times; 10-4 S cm-1, enhanced Li* transference number of 0.5, and improved compatibility with high-voltage cathodes. This work clearly distinguishes the dominant contribution of molecular-level interfacial engineering from the general filler effect, highlighting multifunctional molecular bridges as a promising strategy for high-performance composite solid electrolytes, and providing guidance for the rational design of practical solid-state battery systems. (c) 2026 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Efficient Li+ transport is crucial for ensuring the stability of Li metal anodes in Li metal batteries (LMBs). However, conventional vehicular transport in non-aqueous electrolytes, where Li+ migrates with an intact solvation shell, results in sluggish ion transport kinetics, thereby exaggerating Li+ flux heterogeneity and promoting dendritic deposition. Here, we propose a dipole-mediated solid-liquid interfacial solvation regulation strategy that leverages the abundant interface provided by a nano-ceramic electrolyte coating on the separator to accelerate and homogenize the Li+ transport. The high-dipole molecule 2,5-difluoro-4-nitrobenzoic acid (DNA) was employed to functionalize the ceramic coating, inducing strong ion-dipole interactions with Li+ and lowering the transport energy barrier at the interfacial region. Its low LUMO level further enables preferential reduction to generate a Li3N/LiF-enriched interphase, stabilizing the Li surface and suppressing electrolyte decomposition. As a result, the dipole-regulated interface delivers a high ionic conductivity (0.517 mS cm-1, compared with the pristine separator at 0.308 mS cm-1) and a Li+ transference number of 0.646, enabling dendrite-free Li deposition. Li‖LiFePO4 and Li‖NMC811 full cells exhibit markedly improved long-term cycling stability under high areal-capacity loadings, demonstrating the effectiveness and practical viability of this dipole-mediated interfacial solvation strategy for enhancing ion transport in LMBs.

Electrolytes with anion‐rich solvated structures are promising for high‐voltage lithium metal batteries (LMBs) due to their good interfacial compatibility. Nevertheless, limited Li‐ion transport of these electrolytes has hindered their high‐rate application. Here we demonstrate that Li‐ion transport in anion‐rich solvated electrolytes could be facilitated by designing the coordination topology of anions in the solvation structure. Results show that, for a binary‐anion electrolyte, equal‐molar anions show the most expanded energy level distribution of solvation structures, thus reducing the Li‐ion transport energy barrier, and resulting in a Li‐ion conductivity even higher than that of the commercial carbonate electrolyte at a temperature range from ‐40 °C to 60 °C. More importantly, we identify a universal principle governing the Li‐ion transport enhancement driven by anion configurations: only the combination of anions with multi‐coordination sites shows facilitation in Li‐ion transport, while the combination of centrosymmetric anions with the mono‐coordination site harms it. The diversified anion‐rich solvated structures also form stable interphases on the electrodes, enabling long‐term cycling of 4.5 V LMBs at a high current density of 3.78 mA cm‐2. Overall, our findings shine new light on developing practical electrolytes for energy‐dense LMBs.

Open AccessCCS ChemistryMINI REVIEWS30 May 2024Organic Mixed Ionic-Electronic Conductors for Solid-State Batteries Liyi Zhao, Qingyu Dong, Ruowei Yi, Hui Shao, Yanbin Shen and Liwei Chen Liyi Zhao , Qingyu Dong , Ruowei Yi , Hui Shao , Yanbin Shen and Liwei Chen https://doi.org/10.31635/ccschem.024.202404284 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareFacebookTwitterLinked InEmail Solid-state batteries (SSBs) are considered as the next-generation battery technology, poised to deliver both high-energy and enhanced safety. Nonetheless, their transition from laboratory to market is impeded by several critical challenges. Among these, the solid-solid interfaces within SSBs represent a bottleneck, characterized by issues such as poor physical contact, side reactions, temporal separation, and sluggish charge carrier transfer. Developing key material to construct the efficient solid-solid interface is critical for building high-performance SSBs. Organic mixed ionic-electronic conductors (OMIECs) have emerged as a promising alternative to conventional conductors in addressing the above-mentioned issues owing to their intrinsic properties, including the capability of conducting both ions and electrons, mechanical flexibility, and structural designability. This review will first elucidate the necessity of the integration of OMIECs in SSBs. Next, a comprehensive exploration of the composition, preparation methods, key advantages, and basic characterizations of OMIECs is presented. This review then delves into recent research progress on OMIECs in SSBs, with a special focus on their application in cathode coating layers, the creation of a 3D mixed conductive framework for Li hosting, and their integration as inner layers in Li anodes. Conclusively, potential future applications and innovative designs of OMIECs are discussed. Download figure Download PowerPoint Next article FiguresReferencesRelatedDetails Issue AssignmentNot Yet Assigned Copyright & Permissions© 2024 Chinese Chemical Society Downloaded 0 times PDF downloadLoading ...

Neutral metal-air batteries are of promising practical significance due to their excellent safety, environmental friendliness and strong resistance to carbon dioxide. Among them, the electrochemical performance and stability of air cathode will become a crucial factor restricting the development of neutral metal-air batteries. Herein, gas diffusion layer of an air electrode was constructed by applying different carbon materials including acetylene black (AB), carbon nanotubes (CNT), graphite (GP), ball milled graphite (m-GP) and their mixture with different mass ratios. Corresponding air electrodes were fabricated based on the MnO2/C as the catalyst. For the air electrode AB2@CNT8, its gas diffusion layer was obtained by using the mixture of AB and CNT with a mass ratio of 2:8, and it reveals good oxygen reduction reaction (ORR) performance and high discharge stability when applied to neutral zinc/iron - air batteries. In the neutral chloride electrolyte system, the discharge life of the AB2@CNTCNT8 zinc-air battery reaches 381.39 h and its specific discharge capacity is 765 mA h gZn-1. For the neutral AB2@CNTCNT8 iron-air battery, its specific discharge capacity reaches 863 mA h gFe-1, and it can last a long working time of over 1384 h. In addition, the performance of the air electrode AB2@CNTCNT8 that undergone a long-term operation can be quickly restored by simple hot water treatment. Results indicate that the air electrode AB2@CNTCNT8 has good performance, high stability and durability in the neutral chloride system, and is expected to be a potential candidate for the air cathode of neutral zinc/iron - air batteries.

The formation of stable solid/cathode electrolyte interphases (SEI/CEI) is critical for high-performance alkali metal batteries. While existing research focuses on optimizing SEI/CEI chemistry through electrolyte design, this study introduces a temperature-modulated strategy to control both the chemistry and structure. By combining high-temperature precharging (accelerating Li+ coordination changes and anion decomposition kinetics) with low-temperature storage (reducing solubility of decomposition products), dense and stable interphases form on both electrodes. The robust SEI/CEI enables stable cycling of a 4.5 V Li||NCM811 cell in a medium-concentration ether-based electrolyte, achieving a capacity retention of 88.7% after 200 cycles at 0.5 C (1.5 mAh cm-2). The 1 Ah pouch cells with high-loading cathodes (3.5 mAh cm-2) retain 81.7% capacity after 110 cycles. This study not only offers an economical and efficient approach to enhance the cycling stability of high-voltage lithium metal batteries but also, more importantly, provides new insights into strategies for controlling the formation of SEI to improve the overall battery performance.

Graphite anodes deliver outstanding cycling stability but are limited to a theoretical capacity of 372 mA h g-1. Blending silicon oxide (SiOx) (1600 mA h g-1) with graphite can boost energy density while partially overcoming the drawbacks of each component, yet the composite suffers from the intrinsically low initial coulombic efficiency of SiOx. Prelithiation, adding lithium to the anode before full-cell assembly, is an effective route to recover this first-cycle Li loss and raise ICE, but practical implementation is non-trivial. Ultrathin Li foils (sub 3 mu m) would be ideal prelithiation sources, although producing and handling such fragile foils at scale remain difficult. Moreover, prelithiation kinetics differ markedly between the two active phases: graphite lithiates slowly, leading to non-uniform Li uptake and local over-lithiation, whereas SiOx accepts Li rapidly and homogeneously. This study replaces continuous foils with an array of lithium strips, eliminating the stringent thickness requirement, enables quantitative control of the lithium dose via strip pitch and width, and preserves open gaps that facilitate electrolyte penetration and ion transport. Lithium from the strips is initially absorbed by the SiOx domains; the subsequent diffusion of Li+ into graphite creates a uniform lithium gradient across the electrode and suppresses local over-lithiation. The resulting prelithiated SiOx/graphite anode achieves a 96% ICE and retains 82% of its capacity after 1100 cycles in LiFePO4 full cells without observable structural degradation. The Li-strip array prelithiation strategy, combined with rational SiOx distribution, offers a scalable pathway toward high-energy-density, long-life lithium-ion batteries.

The irreversible formation of solid electrolyte interphase (SEI) reduces lithium-ion batteries' capacity and energy density (LIBs), prompting the prelithiation strategies to compensate for the Li loss. However, the accuracy of the prelithiation degree and the SEI formation under prelithiation conditions remain key issues, especially for practical industrial production. Herein, we demonstrate that roll-to-roll prelithiation of graphite anodes can be done using ultrathin lithium strips (6-mu m-thick), and the prelithiation degree can be precisely tuned by the topological distribution. More importantly, the formation of SEI during the prelithiation process and its influence on the long-term cycling performance of the prelithiated LiFePO4 || graphite pouch cells was revealed. Afterward, the prelithiated pouch LiFePO4 || graphite cell at the optimized conditions exhibits the upgraded energy density after even 1200 cycles. This study shall provide an industrial-scale prelithiation technique for highenergy-density LIBs and a pioneering systematic investigation of SEI chemistry during prelithiation.

Air electrode is an indispensable crucial component of metal-air batteries and its performance is determined by many factors. Among them, the structure of the gas diffusion layer has a great influence on the overall performance of an air electrode. In this work, different carbon materials such as acetylene black (AB), graphite (GP), carbon nanotube (CNT), and their mixtures are taken to construct the gas diffusion layer of an air electrode to significantly improve the gas transport efficiency of the diffusion layer. The results show that the air electrode AB(2)@CNT8, which is composed of AB and CNT with the mass ratio of 2:8, reveals superior oxygen reduction reaction (ORR) performance compared to the AB air electrode fabricated with the conventional carbon material AB. Further, we applied the air electrodes AB(2)@CNT8 and AB to alkaline zinc-air batteries and investigated their discharge performance. Tests show that compared to the AB zinc-air battery, the AB(2)@CNT8 battery exhibits higher output power and discharge specific capacity of up to 704 mAhg(Zn)(-1). In addition, during the ultra-long time constant current (5 mA) discharge test, the AB(2)@CNT8 battery can run stably for 1430 h continuously by simply replacing anode Zn sheet and electrolyte, while maintaining a relatively stable discharge voltage. Meanwhile, the performance of the air electrode AB(2)@CNT8 after long-term operation can be rapidly restored by a simple hot water treatment. Comprehensive testing of the air electrode AB(2)@CNT8 is a testament to its powerful and excellent long life, good cyclic discharge stability, and durability. This shows that changing the type of carbon materials and regulating the mixing ratio between various carbon materials will be an effective means to design and optimize the structure of the air cathode. In addition, the air electrode preparation method of the present investigation has the characteristics of simple synthesis process, easy operation, safety and environmental friendliness, and low cost. The work provides a new strategy for the industrial-scale production of stable and efficient air electrodes.

Lithium (Li) metal is considered ideal for high-energy-density batteries due to its extremely high specific capacity and low electrochemical potential. However, uncontrolled Li dendrite growth and interfacial instability during repeated Li plating/stripping have limited the practical applicability of Li metal batteries (LMBs). Over the past decades, substantial efforts have been devoted to solving the challenges associated with Li metal anodes. Our research team has developed several Li-carbon (Li-C) microsphere composites in recent years to suppress the formation of Li dendrites and achieve a decent cycle life. In this account, we summarize our advances in the design and application of Li-C composites, which include the developments in the structure and chemical composition of high-specific-capacity Li-C composites, strategies for surface passivation of the micro-spherical Li-C composites, and applications of the Li-C composite in next-generation high-energy-density Li-ion, Li-air, and solid-state LMBs. Finally, we discuss future perspectives for developing high-performance Li metal anodes and endeavors to realize the practical applications of LMBs.

Solid electrolyte interphases (SEIs), which are formed by the decom-position of species in the inner Helmholtz plane (IHP) of the elec-trode surface, define the deposition behavior and cycling stability of Li metal anodes. Currently, the IHP is mainly tuned from electro-lyte aspects. In this work, we report that the dominating species in the IHP could be readily controlled via surface dipoles. By self -assembling heteroatomic conjugated molecules on a Cu foil, we con-structed a surface dipole that can increase the adsorption force of the Cu surface to anions, resulting in anion-rich IHP and an anion -derived SEI. The uniform nature of the self-assembled molecule layer and the robust anion-derived SEIs are conducive to uniform Li-deposited morphology, leading to a Li plating/stripping cycling Coulombic efficiency as high as 99.83%. This work sheds new light on tuning the electric double layer at the solid|liquid interface, which is of fundamental importance for the electrochemistry field.

With the growing energy crisis, people urgently need green energy sources to replace fossil ones. As a zero-emission clean energy source, the proton-exchange membrane fuel cell (PEMFC) has received growing attention from researchers due to its broad practical application. However, so far only noble metal Pt can be used as a mature cathodic catalyst for PEMFC to effectively promote the slow kinetic process of the oxygen reduction reaction (ORR). Herein, a low Pt-loading carbon-based catalyst (pCN@NHCS-Fe/Pt-280) with hollow carbon spheres (HCSs), metal-organic frameworks (MOFs), and carbon nanotubes (CNTs) structure was synthesized by the thermal reduction of platinum acetylacetonate and pCN@NHCS-Fe. Compared with the benchmark Pt/C catalyst, pCN@NHCS-Fe/Pt280 presents low cost, and its ORR onset potential (Eonset = 0.971 VRHE) and half-wave potential (E1/2 = 0.883 VRHE) in acidic media are comparable to those of 40% Pt/C (Eonset = 0.965 VRHE, E1/2 = 0.883 VRHE). In the durability test for ORR, its current retention percentage (92.3%) is still higher than 40% Pt/C (86.7%) after 10 000 s of the constant potential test, and its cyclic voltammetry (CV) and linear scan voltammetry (LSV) profiles after 500 cycles exhibit outstanding stability. Moreover, pCN@NHCS-Fe/Pt-280 quickly recovers to 79.1% of the initial value after adding methanol, while 40% Pt/C can recover only to 72.3%, indicating a superior ability in antialcohol oxidation. In addition, the maximum power density of pCN@NHCS-Fe/Pt-280 (518.7 mW cm-2) as the cathode catalyst of PEMFC in the H2-air cell test is also higher than that of Pt/C (515.3 mW cm-2), while its power density is lower than that of Pt/C in the H2-O2 cell test at different pressures due to the high-temperature influence at high current densities. This work provides a valuable idea for the design of multistructured (HCSs, MOFs, CNTs, etc.) electrocatalysts and a feasible strategy for the development of low-Pt-loaded ORR catalysts.

All-solid-state batteries (ASSBs) have been considered a promising candidate for the next-generation electrochemical energy storage because of their high theoretical energy density and inherent safety. Lithium superionic conductors with high lithium-ion transference number and good processability are imperative for the development of practical ASSBs. However, the lithium superionic conductors currently available are predominantly limited to hard ceramics. Practical lithium superionic conductors employing flexible polymers are yet to be realized. The rigid and brittle nature of inorganic ceramic electrolytes limits their application in high-performance ASSBs. In this study, we demonstrate a novel design of a ternary random copolymer single-ion superionic conductor (SISC) through the radical polymerization of three different organic monomers that uses an anion-trapping borate ester as a crosslinking agent to copolymerize with vinylene carbonate and methyl vinyl sulfone. The proposed SISC contains abundant solvation sites for lithium-ion transport and anion receptors to immobilize the corresponding anions. Furthermore, the copolymerization of the three different monomers results in a low crystallinity and low glass transition temperature, which facilitates superior chain segment motion and results in a small activation energy for lithium-ion transport. The ionic conductivity and lithium-ion transference number of the SISC are 1.29 mS.cm(-1) and 0.94 at room temperature, respectively. The SISC exhibits versatile processability and favorable Young's modulus (3.4 +/- 0.4 GPa). The proposed SISC can be integrated into ASSBs through in situ polymerization, which facilitates the formation of suitable electrode/electrolyte contacts. Solid-state symmetric Li parallel to Li cells employing in situ polymerized SISCs show excellent lithium stripping/plating reversibility for more than 1000 h at a current density of 0.25 mA.cm(-2). This indicates that the interface between the SISC and lithium metal anode is electrochemically stable. The ASSBs that employ in situ polymerized SISCs coupled with a lithium metal anode and various cathodes, including LiFePO4, LiCoO2, and sulfurized polyacrylonitrile (SPAN), exhibit acceptable electrochemical stability, including high rate performance and good cyclability. In particular, the Li parallel to LiFePO4 ASSBs retained similar to 70% of the discharge capacity when the charge/discharge rate was increased from 1 to 8C. They also demonstrate long-term cycling stability (> 700 cycles at 0.5C rate) at room temperature. A capacity retention of 90% was achieved even at a high rate of 2C after 300 cycles at room temperature. Furthermore, the SISCs have been applied to Li parallel to LiFePO4 pouch cells and exhibit exceptional flexibility and safety. This work provides a novel design principle for the fabrication of polymer-based superionic conductors and is valuable for the development of practical ambient-temperature ASSBs.

Ni-rich layered oxides are attractive cathode materials for advanced lithium-ion batteries (LIBs) due to their high energy density. However, their large-scale application is seriously hindered by their interfacial instability, especially at a high cut-off potential. Here, we demonstrate that trimethoxyboroxine (TMOBX) is an effective film-forming additive to address the interfacial instability of LiNi0.8Co0.1Mn0.1O2 (NCM811) material at a high cut-off voltage of 4.5 ​V. We find that TMOBX decomposes before carbonate solvent and forms a thin cathode electrolyte interphase (CEI) layer on the surface of the NCM811 material. This TMOBX-formed CEI significantly suppresses electrolyte decomposition at a high potential and inhibits the dissolution of transition metals from NCM811 during cycling. In addition, electron-deficient borate compounds coordinate with anions (PF6−, F−, etc.) and H2O in the battery, further improving the battery's stability. As a result, adding 1.0 ​wt% of TMOBX boosts the capacity retention of a Li||NCM811 ​cell from 68.72% to 86.60% after 200 cycles at 0.5C in the range of 2.8–4.5 ​V.

Herein, we synthesize Fe‐based nanocatalysts supported on the composites composed of hollow carbon spheres (HCSs) and metal–organic frameworks (MOFs) by a facile pyrolysis method. The composites with different ratios of HCSs and MOFs present an interesting phenomenon: the oxygen reduction reaction (ORR) limiting current increases along with the HCSs content, while the onset potential and half‐wave potential show the highest values when the ratio between HCSs and MOFs is optimized. The composite catalysts exhibit superior ORR electrocatalytic performance than Pt/C in alkaline and neutral media. Even in the acidic media, these composite catalysts still present a close catalytic activity to Pt/C. For the oxygen evolution reaction (OER) test, the prepared Fe‐NC@NHCS‐600 shows a reduced overpotential to that of the benchmark IrO 2 . The rechargeable Zn‐air battery using Fe‐NC@NHCS‐600 as the catalyst of air electrode exhibits superior discharge capability with an open‐circuit voltage of 1.620 V and a maximum power density of 278.97 mW cm −2 in alkaline electrolyte, as well as an open‐circuit voltage of 1.457 V and a maximum power density of 114.96 mW cm −2 in neutral electrolyte. The battery also exhibits steady cycling stability for more than 90 and 70 h at 5 and 10 mA cm −2 , respectively.

Prelithiation can replenish active Li into the battery to compensate the Li consumption due to the formation of solid electrolyte interphase (SEI) on the electrode surface, therefore improving the energy density of Li-ion batteries (LIBs), especially for batteries using electrode materials with low initial Coulombic efficiency (ICE). However, practical prelithiation in LIBs is a challenge since most lithiated compounds with high specific capacity are unstable and industrially incompatible. Herein, an effective prelithiation strategy is demonstrated by using a lithium-carbon (Li-C) microsphere composite. These Li-C microspheres are passivated by a self-assembled monolayer of octadecylphosphonic acid, which suppresses the reaction between Li and commonly used slurry solvent 1-methyl-2-pyrrolidinone (NMP). After the addition of passivated Li-C into the NMP-based graphite slurry, the ICE of the graphite||Li half-cell boosts from 88.5% to 100.5%. In a 4.5 V LiCoO2(LCO)||graphite full-cell, the supplementary Li source avoids excessive delithiation of LCO, thus suppressing the destructive phase transformation at high delithiation potential. As a result, the prelithiated LCO||graphite full-cell presents an initial discharge capacity of 201 mAh g(-1) and the capacity retention after 100 cycles increases by 7.1 %. This work provides a practical approach for developing high energy density and long cycle life LIBs.

Ni-rich layered oxide cathode materials, such as LiNi 0.83 Co 0.12 Mn 0.05 O 2 (NCM811), exhibit high specific capacity and low cost, and become cathode material preference of high-energy-density Li-ion batteries. However, these cathode materials are not stable and will form Li-poor reconstructed layers and alkaline compounds (Li 2 CO 3 , LiOH) on the surface during the storage and processing in humid air, resulting in serious deterioration of electrochemical properties. During the past two decades, the consensus on the surface instability mechanism during humid air storage has not been reached. The main controversy focuses on the unstable octahedron mechanism and the Li/H exchange mechanism. Herein, we investigate the instability mechanism in the humid air by conducting scanning electronic microscopy, scanning transmission electron microscopy, and x-ray photoelectron spectroscopy analysis on NCM811 samples stored in designed atmospheres, etc., and realize that the surface instability of the NCM811 during storage should be mainly originated from Li/H exchange when it contacts with moisture.

The nitrogen-doped MXene carbon nanosheet-nickel (N-M@CNi) powder was successfully prepared by a combined process of electrostatic attraction and annealing strategy, and then applied as the separator coating in lithium–sulfur batteries. The morphology and structure of the N-M@CNi were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectrum, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption method. The strong LiPS adsorption ability and high conductivity are associated with the N-doped carbon nanosheet-Ni modified surface. The modified separator offers the cathode of Li–S cell with greater sulfur utilization, better high-rate adaptability, and more stable cycling performance compared with the pristine separator. At 0.2 C the cell with N-M@CNi separator delivers an initial capacity of 1309 mAh g−1. More importantly, the N-M@CNi separator is able to handle a cathode with 3.18 mg cm−2 sulfur loading, delivering a capacity decay rate of 0.043% with a high capacity retention of 95.8%. Therefore, this work may provide a feasible approach to separator modification materials towards improved Li-S cells with improved stability.

Lithium-sulfur (Li-S) batteries hold their promise in renewable next-generation energy storage technologies due to low cost and high theoretical energy. Herein, a Ti3C2Tx MXene-carbon nanocage-sulfur (MXene/CNC/S) cathode is synthesized by a simple process with high conductivity and outstanding performance in Li-S batteries. The cathode with an unusually high sulfur content of 80% demonstrates an eminent initial specific capacity of 1275.5 mAh.g(-1) at 0.1 degrees C and retains 823.8 mAh.g(-1) after 100 cycles, showing a high retention rate of 64.6%. Besides, it exhibits a great conductive feature for rate performance, delivering 630.5 mAh.g(-1) capacity when the current rises to 4 degrees C. In this composition electrode, the excellent electrochemical performance indicates that MXene can effectively adsorb polysulfides to help batteries achieve long-term cyclic performance. On the other hand, the introduction of CNC strongly improves the specific surface area of the cathode and constructs a high conductive network to reduce the stacking of MXene, thus exhibiting better rate performance and increasing utilization of sulfur. Our work holds future technological significance as it could accelerate progress towards lithium-sulfur batteries with high sulfur content and less pricy conductive materials. (C) 2021 Elsevier B.V. All rights reserved.

Herein, a combined method for planetary ball milling and pyrolysis of g‐C 3 N 4 /cobalt phthalocyanine mixture to synthesize Co nanoparticles loaded on CN nanosheets ( g ‐C 3 N 4 @CoPc‐ x with different mass ratios x of g‐C 3 N 4 :CoPc) is proposed. The synthesized catalysts exhibit a unique 3D open sheet‐like structure, and the average size of Co particles is 4.45 nm while encouragingly, a small amount of quasi single‐atom cobalt (mean particle size 0.5 nm) is also found in the samples. In addition, the mass ratio of g‐C 3 N 4 to CoPc presents a significant effect on ORR activity of the samples. Among the samples, g‐C 3 N 4 @CoPc‐3 shows excellent ORR performance with the onset potential of 0.94 V in neutral condition and the half‐wave potential of 1.00 V in alkaline condition, both better than Pt/C. Its onset potentials in acidic (0.83 V) and alkaline (1.07 V) conditions are also comparable to Pt/C. In a full pH range (acidic, alkaline, and neutral) electrolyte, the prepared samples catalyze ORR via a direct four‐electron reaction pathway, and the C 3 N 4 @CoPc‐3 reveals high catalytic stability and high anti‐alcohol tolerance. Results provide wide feasibility for the synthesis and application of g‐C 3 N 4 @CoPc‐3 in fuel cells.