Acetylene Black Carbon Research Articles

Enhanced thermoelectric properties of Ag2Se by manipulation in carrier concentration via acetylene carbon black nanocomposites

Pristine Ag2Se has inherent limitations in its Seebeck coefficient and electronic thermal conductivity, necessitating improvements through carrier concentration manipulation. While its porous structure has been utilized to reduce carrier concentrations, achieving optimal values remains challenging. This study explores enhancing Ag2Se with acetylene carbon black (ACB) nanocomposites to further reduce carrier concentrations and improve thermoelectric (TE) properties. ACB, a cost-effective alternative to other carbon materials, has demonstrated potential in enhancing TE performance in various composites. Ag2Se and ACB composites were synthesized by dispersing different ACB weights in a solution, followed by sintering. Characterization using x-ray diffraction (XRD), Transmission and scanning electron microscopy (TEM and SEM), and other techniques confirmed the phase, structure, and morphology of the composites. The addition of ACB resulted in decreased electrical conductivity and increased Seebeck coefficient in Ag2Se, particularly at ACB concentrations up to 5.0 wt%, balancing the power factor (PF). The total thermal conductivity decreased due to mainly reduced electronic thermal conductivity. The 5.0 wt% ACB sample achieved a zT of approximately 0.8 at 383 K, comparable to the performance of composites using more expensive low-dimensional carbon materials.

Binder‐induced inorganic‐rich solid electrolyte interphase and physicochemical dual cross‐linked network for high‐performance SiOx anode

AbstractSilicon oxide (SiOx) is heralded as the forefront anode material for high‐energy density lithium‐ion batteries, owing to its exceptional specific capacity. Nevertheless, the traditional combination of polyacrylic acid binder and acetylene black conductive carbon continues to struggle with the immense stress induced by the repetitive volume expansion and contraction processes. Here we report a high ionic conductivity, sulfonyl fluoro‐containing binder for SiOx anode via free radical copolymerization reaction between perfluoro (4‐methyl‐3,6‐dioxaoct‐7‐ene) sulfonyl fluoride and acrylic acid. The electrode fabrication process incorporated amino‐functionalized carbon nanotubes (CNT‐NH2) as the conductive agent. A three‐dimensional conductive network structure is constructed through physical and chemical double cross‐linking interactions between the ‐COOH and ‐SO2F functional groups of PAF0.1 binder, the ‐NH2 groups of CNT‐NH2, and the ‐OH groups on the surface of SiOx, including hydrogen bonds and covalent bonds. In addition, the binder induces the formation of a solid electrolyte interphase (SEI) rich in inorganic components such as Li2O, Li2SO3, Li2CO3, and LiF. Benefiting from the synergistic effects of the physically and chemically double cross‐linked three‐dimensional conductive network constructed by the PAF0.1 binder and CNT‐NH2, coupled with the rich‐inorganic SEI, the SiOx anode delivers exceptional rate performance, cycle stability, and lithium‐ion diffusion dynamics.

Effect of Carbon Support on the Properties of Fe, N, S Co-Doped ORR Catalysts Prepared by Molten Salt Method

In recent years, the development of sustainable and environmentally friendly catalysts for various electrochemical processes has become a major focus in the fields of energy storage and fine chemicals. Efficient and cost-effective oxygen reduction reaction (ORR) catalysts are crucial for the advancement of fuel cells and metal-air batteries. This study explores the use of rice husk-based porous carbon (RHPC) with a hierarchically porous structure as a support material for sustainable ORR catalysts. The performance of RHPC was compared with other commercial carbon materials, such as acetylene black (AB) and coconut shell carbon (YP-50), evaluating key properties including particle size, specific surface area, oxygen-containing functional groups, degree of graphitization, and hydrophilicity/hydrophobicity. Compared to AB, which has higher conductivity, and YP-50, which has a greater abundance of oxygen functional groups, RHPC demonstrated significant advantages as a catalyst support. The resulting Fe-NS/RHPC catalyst exhibited high activity (E1/2 = 0.858 V vs RHE, J = 4.83 mA cm−2), outperforming the standard Pt/C (E1/2 = 0.844 V vs RHE, J = 4.99 mA cm−2). When tested in a liquid Zn-air battery, the Fe-NS/RHPC catalyst achieved a peak power density of 116.2 mW cm−2 and a capacity of up to 792.5 mAh g−1.

The Preparation and Performance of Epoxy/Acetylene Carbon Black Wave-Absorbing Foam.

The epoxy foam material filled with an absorbing agent effectively absorbs electromagnetic waves. In this study, epoxy resin was used as the matrix, and acetylene carbon black was used as the magnetic absorbing agent to prepare an absorbing foam material (epoxy/CB). The microstructure of acetylene carbon black (CB) and its distribution in epoxy resin, as well as the effects of pre-polymerization time and CB content on the foam structure, were systematically characterized. Additionally, two dispersion methods, the hot-melt in situ stirring dispersion method and the three-roll milling dispersion method, were studied for their effects on the foaming process and absorbing properties of epoxy/CB. The results showed that with the prolongation of pre-polymerization time, the pore size decreased from 1.02 mm to 0.4 mm, leading to a more uniform pore distribution. Compared to the hot-melt in situ stirring dispersion method, the three-roll milling dispersion method effectively improved the dispersion of CB in epoxy resin, reducing the aggregate size from 300-400 nm to 70-80 nm. The pore diameter also decreased from 0.453 mm to 0.311 mm, improving the uniformity of particle size distribution. However, the absorbing material prepared with the three-roll milling dispersion method exhibited unsatisfactory absorption performance, with values close to 0 dB at mid-low frequencies and around -1 dB at high frequencies. In contrast, the absorbing material prepared with the hot-melt in situ stirring dispersion method showed better absorption performance at high frequencies, reaching around -9 dB.

Process Parameter Optimization via RSM of a PEM based Water Electrolysis Cell for the Production of Green Hydrogen

In the present work, the operating parameters were optimized using Box Behnken Design (BBD) in response surface methodology (RSM) to maximize the hydrogen production rate (R1) and hydrogen production rate per unit watt consumed (R2) of a proton exchange membrane electrolysis cell (PEMEC), a third response (R3) which was the sum of the scaled values of R1 and R2 were selected to be maximized so that both hydrogen production rate and hydrogen production rate per unit watt consumed could be maximized. The major parameters which were influencing the experiment for enhancing the output responses were oxygen electrode/anode electrocatalyst loading (A), current supplied (B) and water inlet temperature (C). The commercial proton exchange membrane Nafion® was used as the electrolyte. The acetylene black carbon (CAB) supported IrO2 was used as the electrocatalyst for preparing oxygen electrode/anode whereas commercial Pt (40 wt%)/CHSA was used as the H2 electrode/cathode electrocatalyst. The quadratic model was developed to predict the output/responses and their proximity to the experimental output values. The developed model was found to be significant as the P values for both the responses were < 0.0001 and F values were greater than 1. The optimum condition for both the responses were O2 electrode/anode electrocatalyst loading of 1.78 mg/cm2, supplied current of 0.33 A and water inlet temperature of 54°C. The predicted values for hydrogen production rate (R1) and hydrogen production rate per unit watt consumed (R2) were 2.921 mL/min and 2.562 mL/(min·W), respectively obtained from the quadratic model. The error % between the predicted response values and experimental values were 1.47% and 3.08% for R1 and R2, respectively. This model predicted the optimum conditions reasonably in good agreement with the experimental conditions for the enhancement of the output responses of the developed PEM based electrolyser.

Analysis of cooperative effects between activated carbons and acetylene black using electrochemical, rheological and textural characterizations to maximize supercapacitance

The interactions arising in Electrochemical Double Layer Capacitors (EDLC) made up of commercial activated carbons (DLC 50 Norit, TF-B520 and Kuraray YP-80 F), acetylene carbon black (AB) and polytetrafluoroethylene (PTFE) are analyzed with the aim of maximizing their specific capacitances. AB is varied (0–10 wt%, 0–20 wt% only for further exploration of TF-B520) to minimize its content, while maintaining fixed the PTFE composition. The best rate capabilities are obtained at 5 wt% AB for TF-B520 and Kuraray YP-80 F, and 4 wt% AB for DLC 50 Norit on the basis of cyclic voltammetry, charge/discharge curves and electrochemical impedance spectroscopy. These results strongly depend on a minimum amount of AB in the composite determined through conductivity measurements (i.e. percolation threshold), which guarantees its electronic conductivity. According to N2 adsorption/desorption and textural studies, the critical property defining the electrode supercapacitance is its specific surface area (SSA), relying considerably on the surface area of the pristine AC (main component), regardless of its pore volume and size, or AB area. The specific capacitances present the following trend: TF-B520 (1711–1830 m2 g−1) > > (1356–1571 m2 g−1) > (1319–1504 m2 g−1). Viscoelasticity properties of the composites are less important than conductivity or SSA, since mechanical pressure alters the AC-AB interparticle network, generating better percolating media. In order to optimize specific capacitance, a balance is required between electronic conductivity (percolation in the porous media by AB) and ionic transference (specific surface area of AC) in the electrode composite.

FeF3/(Acetylene Black and Multi-Walled Carbon Nanotube) Composite for Cathode Active Material of Thermal Battery through Formation of Conductive Network Channels.

Considerable research is being conducted on the use of FeF3 as a cathode replacement for FeS2 in thermal batteries. However, FeF3 alone is inefficient as a cathode active material because of its low electrical conductivity due to its wide bandgap (5.96 eV). Herein, acetylene black and multi-walled carbon nanotubes (MWCNTs) were combined with FeF3, and the ratio was optimized. When acetylene black and MWCNTs were added separately to FeF3, the electrical conductivity increased, but the mechanical strength decreased. When acetylene black and MWCNTs were both added to FeF3, the FeF3/M1AB4 sample (with 1 wt.% MWCNTs and 4% AB) afforded a discharge capacity of approximately 74% of the theoretical capacity (712 mAh/g) of FeF3. Considering the electrical conductivity and mechanical strength, this composition was confirmed to be the most suitable.

A new 3D Zn-based MOF with enhanced UV-light promoted photocatalytic activity for dye degradation

A new 3D Zn(II)-based metal-organic framework [(CH3)2NH2]2[Zn5(TTC)4] (1) (H3TTC = 2,2′:6′,2″-terpyridine-4,4′,4″-tricarboxylic acid) has been solvothermally synthesized and characterized. The single crystal X-ray diffraction for 1 indicate that it possess (3,4,4)-connected network with Schläfli symbol (4.84.10)4(84.102)4(4.82). Apart from the structural investigation, the photocatalytic performance of MOF 1 to photo-decompose aqueous solution of model dyes viz. methyl violet (MV), Rhodamin B (Rh B), acetylene carbon black (ACB) and methyl blue (MB) have been examined. The photodecomposition results suggest the Zn(II)-MOF based catalyst exhibits best potential to photodegrade MB dye under UV light irradiation. Effect of photocatalyst dosage and initial MB dye concentration on the photocatalytic properties suggest that the photocatalyst exhibits best activity at 50 mg photocatalyst dosage and 18 ppm of initial dye concentration. The plausible photocatalytic mechanistic pathway of MB dye in the presences of 1 has been established with the aid of trapping experiments and density of states (DOS) calculations.

Effect of high aspect ratio additives on microstructural and mass transport properties of the microporous layer in a proton exchange membrane fuel cell

Tuning up transport properties of the microporous layer is an effective way to enhance mass transport in a proton exchange membrane fuel cell. The incorporation of non-spherical conductive additives in the conventional microporous layer can modify its pore structure. In this study, 5, 20, and 50 wt.% of two high aspect ratio additives, multiwall carbon nanotube and graphene nanoplatelet, are mixed with the acetylene-black carbon to systematically study their impact on ink and the final diffusion media properties. Using a bottom-up approach, the rheological properties of the ink are correlated to the mass transport resistance in the diffusion media. The ink with additives exhibits rheological properties of a less compact microstructure with large agglomerates. Whereas, a more compact agglomerated network is observed from the ink with pure acetylene black carbon nanoparticles. Graphene nanoplatelet has a dominating effect on the surface quality of the microporous layers due to its two-dimensional structure. The test results show that the microstructure formed by the synergy of acetylene black and additives can enhance ohmic and mass transport performance. 20 wt.% of the additive loading is found to be optimal and multiwall carbon nanotube shows the best fuel cell performance.

Cost-effective water-soluble three-dimensional cross-linked polymeric binder for high-performance lithium‑sulfur batteries

In lithium–sulfur (LiS) batteries, the feasible sulfur-cathode applications are limited mainly by the rapid capacity loss and poor cycle life of the cathodes because of the considerable volumetric expansion, sulfur insulation, and polysulfide formation. To solve these problems, a water-soluble three-dimensional (3D) binder network was developed using organic poly(vinyl alcohol) (PVA) crosslinked with a boric acid (BA). Different BA concentrations (0, 0.035, 0.07, and 0.105 M) were used to compare the LiS battery performances. The PVA–BA0.07 binder exhibited a higher strength at breakage (31 MPa) than the PVA–BA0, PVA–BA0.035, and PVA–BA0.105 binders (12, 17.5, and 19.1 MPa, respectively). To prepare the acetylene‑carbon black (AB)/sulfur (S) composite (ABS), elemental S was added to acetylene‑carbon black (AB) using heat diffusion. The prepared 3D-crosslinked polymeric binder effectively reduced the volumetric expansion and lithium polysulfide formation during cycling. Moreover, the boron (B), which is electron deficient, freely accepted electrons during cycling and, thus, helped form an effective solid electrolyte interface layer. The obtained lithium borate species considerably suppressed the interfacial side reactions and increased the initial coulombic efficiency. The PVA–BA0.07 binder with ABS electrode exhibited an outstanding cycling performance at a high sulfur loading. After 300 charge/discharge cycles at 0.2 C-rate, the PVA–BA0.07 containing electrode exhibited a high discharge capacity and sulfur loading of 946.8 mAh/g and up to 3.5 mg/cm2, respectively. The study findings will enable the development of high-performance LiS batteries using cost-effective water-soluble 3D-crosslinked polymeric binders.

The Effect of Acetylene Carbon Black (ACB) Loaded on Polyacrylonitrile (PAN) Nanofiber Membrane Electrolyte for DSSC Applications

Nanofiber membranes are starting to be used as an electrolyte storage medium because of their high porosity, which causes ionic conductivity, producing high energy. The ability of nanofiber membranes to absorb electrolytes proves their stability when used for a long time. In this study, the loading of acetylene carbon black (ACB) on polyacrylonitrile (PAN) is made by the electrospun method, which in turn is applied as an electrolyte medium in DSSC. Materials characterization was carried out through FTIR to determine the functional groups formed and SEM to observe morphology and diameter distribution. Furthermore, for DSSC performance, efficiency and EIS tests were carried out. The optimum nanofiber membrane was shown by esPACB1, with the highest efficiency reaching 1.92% with a porosity of 73.43%, nanofiber diameter of 172.9 ± 2.2 nm, an absorbance of 1850, and an electron lifetime of 0.003 ms.

Water adsorption on acetylene black carbon

Differential heat, isotherm, thermokinetics, and entropy of water adsorption on the black carbon were studied by the adsorption-calorimetric method at 303 K. The adsorption mechanism, type, and number of formed ion-molecular complexes were determined. Thermokinetics of adsorption on the black carbon and the law of migration of exchange cations were determined, and the adsorption energy of gases and vapors was calculated. The adsorption isotherm is described by the two-and three-dimensional mathematical equations of the volume-saturation theory of micro-pores (TVSM).

Design of active-material/solid-electrolyte composite particles with conductive additives for all-solid-state lithium-ion batteries

All-solid-state lithium-ion batteries (ASSLIBs) are promising candidates for next-generation electric vehicle batteries. The contact interface between the active material (AM) and solid electrolyte (SE) is an important factor that affects the performance of ASSLIB. Composite particles, which are SE-coated AM particles, can form electrodes with large AM-SE contact interfaces. However, they can decrease in cell capacity because of the SE coating layer with electrical non-conductance. This study designed composite particles with conductive additives (CAs) using dry-coating. Acetylene black (AB) and vapor-grown carbon fiber (VGCF) were used as typical CAs, and the composite particles with these CAs were compared with those without CAs and simple mixture. Although the addition of CAs improved the cell capacity and decreased internal resistance, the type of CA significantly affected the rate performance. Because the VGCFs were barely incorporated into the SE coating layer, the incorporation of VGCFs did not improve the rate performance. However, the ABs were effectively incorporated into SE coating layer, resulting in the best rate performance in this study. This difference was due to the ease of supplying electrons to the AM particles. Therefore, AB was suitable for the CA of the composite particles to improve the performance of the ASSLIB.

Performance of polymer electrolyte fuel cell under wet/dry conditions with hydrophilic and hydrophobic electrospun microporous layers

The electrospinning method is used to fabricate the microporous layers (MPL). The hydrophobic and hydrophilic electrospun MPLs (E-MPLs) are realized by using acetylene black and pigmented carbon black in the electrospinning ink, respectively. Scanning electron microscope shows that the E-MPLs have three-dimensional inter-connected pore structure formed by disordered nanofibers. Mercury intrusion porosimetry results indicate that the E-MPLs have larger porosity (more than 85%) and wider pore size distribution (0.8–4 μm) compared with the commercial MPL (from SGL 29BC). Hydrophobic E-MPL exhibits lower mass transport resistance at 100% relative humidity (RH) due to its larger pore size and better water drainage capability, while the hydrophilic E-MPL shows lower ohmic resistance at 40% RH due to its higher water retention capability. Fuel cell with a double-layer E-MPL, an integrated MPL containing a hydrophilic layer and a hydrophobic layer, is found to perform well under wider RH range. The fuel cell with double-layer E-MPL is found to have a better dynamic response to a current step, in that it has lower amplitude of voltage undershoot and overshoot, and reaches a steady state more quickly.

Strain Sensing Behavior of 3D Printable and Wearable Conductive Polymer Composites Filled with Silane-Modified MWCNTs.

3D printing of conductive polymers is an attractive technique for achieving high flexibility, wearability, and sensing characteristics without geometrical limitations. However, there is an urgent need to integrate printability, conductivity, and sensing capability. Herein, a conductive polymer ink for 3D printing that combines the desirable features of high electrical conductivity, flexible stretchability, and strain-sensing monitoring is prepared. The ink matrix is polydimethylsiloxane and synergistically enhanced by acetylene carbon black (ACB) and multi-walled carbon nanotubes (MWCNTs) (silane or un-silane-modified). The inks are screened step-by-step to explore their printability, rheology, mechanical properties, and electrical performance upon loading. The formation of an electrically conductive network, electrical properties upon tensile load, and strain sensing stability under cyclic stretching are investigated intensively. It is demonstrated that conductive polymers filled by ACB and silane-modified, MWCNTs (MWCNTs-MTES) possess superior printability, stretchability, conductivity, and strain sensing behaviors. Finally, a flexible wearable strain-sensing skin patch is printed, and it successfully records joint motion signals on human fingers, wrists, and elbows with good stability and repeatability. Those results show the extent of potential applications in healthcare and motion monitoring fields. This work provides an efficient and simple route to achieve comfortably wearable and high-performance strain sensors.

Bismuth telluride anode boosting highly reversible electrochemical activity for potassium storage

To ensure high capacity with reasonable cycling stability using the conversion or K-alloy reaction, the anode should minimize or embrace the volume expansion during the discharge (potassiation) and charge (depotassiation) processes. Herein, we report on a Bi2Te3 composite modified by nanosized carbon that boosts the highly reversible capacity with long cycling stability. The as-synthesized Bi2Te3 powders and acetylene black carbon were compositized via high-energy ball-milling, resulting in improvement of the electrical conductivity to ∼10−4 S cm−1 from ∼10−7 S cm−1. Electrochemical investigation revealed that the proposed Bi2Te3@C retained over 79.8% of its initial capacity (311 mAh g− 1) for 500 cycles at a current of 1000 mA g− 1. We unveil the reaction chemistry behind the acceptable performance using operando X-ray diffraction, X-ray absorption near edge structure spectroscopy, and time-of-flight secondary-ion mass spectrometry. The Bi2Te3 undergoes a conversion reaction to form Bi0 metal and K2Te as a conversion byproduct, after which Bi is further potassiated to K3Bi. The highly reversible behavior is attributed to the enlargement of the active area along with the filling of voids among Bi2Te3 particles by nanosized carbons in the composite electrode, enabling not only facile electron transport but also preservation of the electrode shape even after long-term cycling. Our approach highlights the feasibility of applying Bi2Te3@C as a sustainable anode material for potassium-ion batteries.

Fully integrated flexible long-term electrocardiogram recording patch with gel-less adhesive electrodes for arrhythmia detection

A mechanically flexible and fully integrated electrocardiogram (ECG) recording patch (ERP) that simultaneously monitors the ECG signals and detects the arrhythmia is presented. A simplified two-step process is applied to fabricate the acetylene carbon black (AB)/ polydimethylsiloxane (PDMS) electrodes. The soft and adhesive nature of polymer composite electrodes allows conformal contact to the skin. The ERP integrates ECG front end circuits, microcontroller chip and wireless communication unit on a flexible printed circuit boards (FPCB) with electrodes attached on its back, which bridges the technological gap among the signal acquisition, processing, and wireless transmission in the wearable electronics. The ERP can be deformed easily under stretching and bending actions by a special connection of two squares through serpentine traces. With the concentration of 7 wt% AB, the average signal-to-noise ratio (SNR) of the built electrodes at different postures (sit, stand and walk) during electrocardiography are assessed as 17.4 dB, 16.1 dB and 5.6 dB, respectively. Similarly, the SNR of the ERP with Ag/AgCl electrodes are 22.1 dB, 20.6 dB and 10.3 dB, respectively. The performance of the AB/PDMS electrodes are very close to the standard Ag/AgCl electrodes. In addition, the ERP have the ability of anti-interference from environmental noise and motion artifacts (MA). Benefited from implemented microcontroller unit (MCU) platform, the ERP allows sophisticated signal processing with the introduction of discrete wavelet transform (DWT) and support vector machine (SVM) algorithms, which achieves high classification accuracy of 98.7% for online arrhythmia detection. The designed platform provides a wide range of applications for other personalized physiological monitoring and diagnosis.

Study on the effect of calcium hypochlorite and air as mixed oxidant and a synthesized low cost Pd‐Ni/C anode electrocatalyst for electrooxidation of glycerol in an air breathing microfluidic fuel cell

AbstractIn the present work, glycerol‐based air breathing microfluidic fuel cell (μFC) is investigated. The noble metal Pd and non‐noble metal Ni‐based bimetallic synthesized electrocatalyst (Pd‐Ni/C) were used for glycerol electrooxidation and commercial Pt/CHSA was used as cathode electrocatalyst. The anolyte is glycerol mixed with KOH electrolyte. The atmospheric air and calcium hypochlorite mixture are used as oxidant in cathode and catholyte, respectively. Acetylene black carbon is used as electrocatalyst support with low metal loading of 20 wt% Pd and Ni at their different weight ratios (Pd/Ni) of 16:4, 10:10, and 4:16 to synthesize bimetallic Pd‐Ni/C anode electrocatalysts. The crystal structure of the synthesized electrocatalyst was determined by X‐ray diffraction (XRD) analysis. The surface morphology and surface concentration of synthesized electrocatalyst were determined by scanning electron microscopy (SEM) and energy dispersive X‐ray spectroscopy (EDX), respectively. The particle size of synthesized electrocatalyst was determined by transmission electron microscopy (TEM) analysis. The electrochemical activity of Pd‐Ni/C was investigated by cyclic voltammetry analysis. The electrocatalyst Pd‐Ni (10:10)/C gives higher electrocatalytic activity for glycerol electrooxidation compared to other ratios of electrocatalyst. A single air breathing μFC is investigated using various key parameters where air alone as oxidant gives open circuit voltage (OCV) of 0.42 V and maximum power density of 1.27 mW/cm2. While using calcium hypochlorite and air as mixed oxidant, the OCV was increased to 0.72 V and maximum power density increased to 3.43 mW/cm2, which are 1.71 and 2.7 times, respectively, more than that of air as oxidant only.

A practical approach to design sulfur host material for lithium-sulfur batteries based on electrical conductivity and pore structure

Lithium-Sulfur (Li–S) batteries have emerged as one of the most promising batteries and as a next-generation energy source owing to their excellent gravimetric energy density. Sulfur is abundant in nature. Carbon materials have been widely used as sulfur host materials owing to their high electrical conductivity and large surface area. As the host materials highly influence the performance of Li–S batteries, their properties should be well designed. Therefore, understanding the significance of the properties of these materials as sulfur hosts is important in the practical design of electrodes. In this study, sulfur composite cathodes were fabricated using acetylene black (AB) and active carbon (AC) to investigate the effect of the carbon host material on the performance of the Li–S batteries. AB has a higher electrical conductivity and a smaller surface area compared to AC. The sulfur composite cathode with AB shows excellent cycling and kinetic performance compared with the sulfur composite cathode with AC, even though AC has a larger surface area, indicating that the cycling and kinetic performance of the Li–S battery is dominantly affected by the electrical conductivity of the carbon host.

An overlooked issue for high-voltage Li-ion batteries: Suppressing the intercalation of anions into conductive carbon

Summary High-voltage Li-ion batteries have been extensively studied to increase energy density of batteries. However, their cycling stability has remained poor, despite various strategies being proposed to overcome the issues of high-potential cathodes, such as electrolyte oxidation and transition metal dissolution. Herein, we report anion intercalation into the cathode conductive carbon as an overlooked yet critical issue. We propose a concentrated sulfolane (SL)-based electrolyte that prevents anion intercalation via two mechanisms: (1) by offering a high activation barrier to intercalation via its strong anion-Li+ interaction and (2) by forming a sulfur-containing, anion-blocking SL-derived interphase. This electrolyte, used with graphitized acetylene black, which is oxidatively stable but usually susceptible to anion intercalation, enables the stable operation of a Li2CoPO4F/graphite full cell (cut-off voltage = 5.2 V), with 93% capacity retention after 1,000 cycles and an average Coulombic efficiency of ≥99.9%. This is a pivotal strategy to enhance the reversibility of >5 V Li-ion batteries on a commercial level.