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[Display omitted] Flexible electrodes based on conversion-type materials have potential applications in low-cost and high-performance flexible sodium-ion batteries (FSIBs), owing to their high theoretical capacity and appropriate sodiation potential. However, they suffer from flexible electrodes with poor mechanical properties and sluggish reaction kinetics. In this study, freestanding CoS 2 nanoparticles coupled with graphene oxides and carbon nanotubes (CoS 2 /GO/CNTs) flexible films with robust and interconnected architectures were successfully synthesized. CoS 2 /GO/CNTs flexible film displays high electronic conductivity and superior mechanical properties (average tensile strength of 21.27 MPa and average toughness of 393.18 KJ m−3) owing to the defect bridge for electron transfer and the formation of the π–π interactions between CNTs and GO. In addition, the close contact between the CoS 2 nanoparticles and carbon networks enabled by the Co-N chemical bond prevents the self-aggregation of the CoS 2 nanoparticles. As a result, the CoS 2 /GO/CNTs flexible film delivered superior rate capability (213.5 mAh g−1 at 6 A g−1, better than most reported flexible anode) and long-term cycling stability. Moreover, the conversion reaction that occurred in the CoS 2 /GO/CNTs flexible film exhibited pseudocapacitive behavior. This study provides meaningful insights into the development of flexible electrodes with superior mechanical properties and electrochemical performance for energy storage. [ABSTRACT FROM AUTHOR]

[Display omitted] The olivine lithium iron phosphate (LFP) cathode has gained significant utilization in commercial lithium-ion batteries (LIBs) with graphite anodes. However, the actual capacity and rate performance of LFP still require further enhancement when combined with high-capacity anodes, such as silicon (Si) anodes, to achieve high-energy LIBs. In this study, we introduce a gelatin-derived carbon network into a nanosized LFP cathode without the need for additional binding and conductive agents, employing a simple and cost-effective method. The resulting cathode exhibits an extremely high LFP content (∼92.3 wt%), enabling it to show a high real capacity of 159.7 mAh/g at 0.2 C in half cells. Additionally, the interconnected carbon network effectively facilitates electron and Li+ transport, providing rapid pathways within the LFP nanoparticles. Consequently, the cathode exhibits superior rate capability (107.3 mAh/g at 10 C) and good cycling performance (with a capacity retention of ∼ 80 % after 500 cycles). To further assess its practical viability, the LFP cathode is assembled into a full cell utilizing a Si-based anode with a N/P ratio of 1.1. The resulting full cell delivers a significantly high energy density of 419.7 Wh kg−1, coupled with prolonged cycle life, highlighting its promising prospects for practical applications. [ABSTRACT FROM AUTHOR]

Cathode active materials and conductive additives for thermal batteries operating at high temperatures have attracted research interest, with a particular focus on compounds offering high thermal stability. Recently, FeF3 has been proposed as a candidate for high-voltage cathode materials; however, its commercialization is hindered by its low conductivity. In this study, conductive additives, such as Ni-coated carbon composites (multi-walled carbon nanotubes (MWCNTs) and carbon black (CB)), were utilized to enhance the thermal stability and conductivity of FeF3. The incorporation of metal–carbon conductive additives in the FeF3 composite increased the thermal stability by more than 10 wt.% and ensured high capacity upon conductivity enhancement. The FeF3@Ni/MWCB 15 wt.% composite containing 30 wt.% Ni exhibited a discharge capacity of ∼86% of the theoretical capacity of 712 mAh/g. The use of Ni-coated carbon-based conductive additives will allow the application of FeF3 as an effective high-temperature cathode material for thermal batteries. [ABSTRACT FROM AUTHOR]

Na3V2(PO4)3/C powders were prepared by using various amounts of surfactant additives such as cetyltrimethylammonium bromide (CTAB), polyvinyl pyrrolidine (PVP), and mixed CTAB-citric acid. The structural, microstructural, and electrochemical properties were analyzed by various characterization methods such as X-ray diffractometry, electron microscopy, cyclic voltammetry, and galvanostatic charge and discharge techniques. Single-phase Na3V2(PO4)3 (NVP) with rhombohedral crystal structure was obtained for all organic additives by calcination at 850 °C for 6 h in an Ar/10 vol.% H2 atmosphere. The rather large NVP particles (~ 300–500 nm) were dispersed on a continuous 3D carbon network which was in situ generated by burning the organic additives. However, the NVP powders prepared by PVP surfactant had the bulky morphology with a plenty of pores. Among the organic additives, the mixed CTAB-citric acid additive showed the better electrochemical properties including high capability rate (104 mAh g−1 @1C) and high cycling performance (capacity retention of 97.5%). [ABSTRACT FROM AUTHOR]

Transition metal oxides with various valence states have high specific capacitance and have attracted much attention. However, the poor cycle stability caused by material agglomeration seriously limits the play of its high activity. Herein, we create a stress dispersion structure (CuxO composite porous carbon net) by in situ lyophilization and one-step carbonization, effectively anchoring highly reactive copper oxides and highly conductive carbon networks combined with high nitrogen doping of 10.7%, to investigate their electrochemical performance in supercapacitors. Specifically, the specific capacitance of CuxO@NPC can be as high as 392 F/g (0.5 A/g) in the three-electrode system with 6 mol/L KOH as electrolyte. When applied to the two-electrode system, the cycle stability of the whole device can reach 97% after 10,000 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] Cobalt selenide, as a star material in battery industry, has attracted much attention. However, when it is applied solely in sodium ion batteries, it will cause large volume expansion and material agglomeration, which will seriously affect the overall performance of batteries. In this work, we use ice bath impregnation to combine CoSe 2 nanoparticles with porous nitrogen-doped carbon networks (NC) as advanced anodes for ultra-long cycle life sodium ion batteries (SIBs). CoSe 2 nanoparticles are evenly attached to NC with strong interfacial contacts in CoSe 2 @NC. The strong contact of CoSe 2 on the porous carbon network, along with the carbon network's unique network cross-linking structure, results in rapid electron transfer and Na ion diffusion kinetics of CoSe 2 @NC, resulting in superior electrochemical performance. Besides, we have synthesized CoSe 2 @NC with different loading by changing Co2+ concentration. The results show that CoSe 2 @NC anode thus provides a high reversible capacity of 406 mAh/g. In addition, at high current 5 A/g, it can keep a reversible capacity of 300 mAh/g after 4500 cycles with an average capacity loss of less than 0.01 % per cycle. The excellent anchoring structure enables it to form stable solid electrolyte film (SEI) and reduce the amount of dead sodium in the first charge–discharge process, showing high Initial Coulombic Efficiency (ICE) (89.2 %). Finally, CoSe 2 @NC and Na 3 V 2 (PO 4) 3 (NVP) are assembled into a full cell and the results shows an ultra-long cycle stability at 0.1 A/g. This strategy will facilitate the application of transition metal selenides in next-generation energy storage systems. [ABSTRACT FROM AUTHOR]

As an important part of lithium-sulfur battery (LSB), separator not only provides ion transport channel but also plays a key role in ensuring battery safety. However, the aperture of the commercial separator polypropylene (PP) is relatively large, which cannot effectively inhibit the migration of polysulfides generated during the charging and discharging process between the positive and negative electrodes, resulting in a decrease in the cycle stability of LSB. In this work, a modified LSB separator Ni 3 S 2 -NiO@AC-4@PP is designed, which is anchored by Ni 3 S 2 -NiO heterojunction on volcanic rock-like three-dimensional porous carbon network (AC) as the functional interlayer. The AC possesses a large specific surface area and excellent electrical conductivity, creating sufficient space for the physical and chemical adsorption of insoluble polysulfides. The Ni 3 S 2 -NiO heterojunction is embedded and attached to the AC, which helps to hinder the diffusion of polysulfides and accelerate the redox reaction. It is also confirmed by density functional theory (DFT) calculation that Ni 3 S 2 -NiO heterojunction inhibited the shuttle of polysulfides through the adsorption capacity of NiO and the catalytic activity of Ni 3 S 2. Thus, the Ni 3 S 2 -NiO@AC-4@PP battery exhibits an elevated initial specific capacity of 1027.8 mAh g−1 at 0.2C, maintaining long-term stability after 200 cycles with the capacity retention rate of 81.4 %. At the higher current density (2C), Ni 3 S 2 -NiO@AC@PP battery demonstrates durable cycle with the capacity retention rate of 91.3 %. This study proposes a new feasible strategy to obtain high-performance, low-cost modified separators by designing functional interlayers with excellent adsorption and catalytic properties. This work constructs a functional interlayer Ni 3 S 2 -NiO@AC modified lithium-sulfur battery separator by utilizing Ni 3 S 2 -NiO heterojunction and three-dimensional porous carbon network AC, which not only significantly promotes the transformation of polysulfides, but also provides a innovative tactics for constructing functional separator to raise the battery efficiency of LSBs. [Display omitted] • Volcanic rock-like functional interlayer Ni 3 S 2 -NiO@AC nanomaterial was prepared. • Synergistic effect of Ni 3 S 2 -NiO heterojunction and AC improves LSB performance. • Ni 3 S 2 -NiO@AC-4@PP battery exhibits excellent cycle stability. [ABSTRACT FROM AUTHOR]

Cathode active materials and conductive additives for thermal batteries operating at high temperatures have attracted research interest, with a particular focus on compounds offering high thermal stability. Recently, FeF3 has been proposed as a candidate for high-voltage cathode materials; however, its commercialization is hindered by its low conductivity. In this study, conductive additives, such as Ni-coated carbon composites (multi-walled carbon nanotubes (MWCNTs) and carbon black (CB)), were utilized to enhance the thermal stability and conductivity of FeF3. The incorporation of metal–carbon conductive additives in the FeF3 composite increased the thermal stability by more than 10 wt.% and ensured high capacity upon conductivity enhancement. The FeF3@Ni/MWCB 15 wt.% composite containing 30 wt.% Ni exhibited a discharge capacity of ∼86% of the theoretical capacity of 712 mAh/g. The use of Ni-coated carbon-based conductive additives will allow the application of FeF3 as an effective high-temperature cathode material for thermal batteries.

10%-γGCMO was successfully prepared based on mechanical stress preparation of γ-GY. The formation of S-scheme heterojunctions at the interface accelerated the migration between catalysts and enhanced the redox ability of 10%-γGCMO. The heterojunction type between γ-GY and CuMoO 4 was determined as S-scheme heterojunction as well as the electron migration path between the catalysts base on in situ radiation XPS spectroscopy and Density Functional Theory (DFT) as the theoretical guidance. [Display omitted] • γ-GY was successfully prepared by mechanical stress. • γ-GY/CuMoO 4 S-scheme heterojunction was constructed. • The 10%-γGCMO shows excellent photocatalytic hydrogen evolution activity. • In situ radiation XPS spectrum and density functional theory (DFT) were used as theoretical guidance. The introduction of novel materials is crucial to broaden the development of the field of artificial photosynthesis. The high recombination rate of photogenerated carriers remains one of the fundamental reasons that hinder the development of photocatalysis. In view of this, we coupled γ-GY containing alkyne bonds with CuMoO 4 to form interfacial S-scheme heterojunctions. The formation of S-scheme heterojunctions accelerates the electron transfer and improves the separation efficiency of photogenerated carriers, while enhancing the photoreduction ability of the composite catalysts and allowing more electrons to participate in the reduction reaction of H+ under light conditions. The heterojunction type between γ-GY and CuMoO 4 was determined as S-scheme heterojunction as well as the electron migration path between the catalysts base on in situ radiation XPS spectroscopy and Density Functional Theory (DFT) as the theoretical guidance. This work provides a basis for the structural optimization of γ-GY based on in situ and theoretical calculations, and expands the application of mechanical preparation of γ-GY in photocatalysis. [ABSTRACT FROM AUTHOR]

Transition metal oxides with various valence states have high specific capacitance and have attracted much attention. However, the poor cycle stability caused by material agglomeration seriously limits the play of its high activity. Herein, we create a stress dispersion structure (CuxO composite porous carbon net) by in situ lyophilization and one-step carbonization, effectively anchoring highly reactive copper oxides and highly conductive carbon networks combined with high nitrogen doping of 10.7%, to investigate their electrochemical performance in supercapacitors. Specifically, the specific capacitance of CuxO@NPC can be as high as 392 F/g (0.5 A/g) in the three-electrode system with 6 mol/L KOH as electrolyte. When applied to the two-electrode system, the cycle stability of the whole device can reach 97% after 10,000 cycles.

Performance of polyaniline was dramatically enhanced by engineering robust PANI/carbon interfaces, and a proton supercapacitor with high energy/power densities was further demonstrated based on the prepared PANI cathode and an h-WO 3 anode. [Display omitted] Supercapacitors are high power energy storage devices, however, their application are remain limited by the low energy density. Developing high capacity electrode materials and constructing devices with high operating voltage are effective ways to solve this problem. Herein, performance of polyaniline (PANI) electrode materials is dramatically enhanced by engineering robust PANI/carbon interfaces, through assembling PANI nanorod array on rose petals derived carbon network (RPDCN). The structure of the PANI is optimized by adjusting the concentration of the aniline precursor. The unique structure enables the prepared PANI/RPDCN composite show a high capacitance of 636 F g−1 at 0.5 A g−1, based on the total weight of PANI and RPDCN substrate. The robust interface effectively prolonged the composite electrode stably cycled for over 2000 cycles at 2 A g−1 with a capacity retention of 89%. When coupled with a hexagonal tungsten oxide (h-WO 3) anode, a high-power asymmetric proton supercapacitor with high energy densities (29.0 Wh kg−1/0.61 kW kg−1 and 21.4 Wh kg−1/19.51 kW kg−1) was assembled. This work provides an effective and eco-friendly route toward superior PANI electrodes and proposes a promising high-power energy storage system using proton as working ion. [ABSTRACT FROM AUTHOR]

A three-dimensional MnO/C nanocomposite is fabricated through a simple route of immersion and subsequent calcination. The carbon content and morphology of the sample are adjusted by adjusting the calcination temperature. This material combines the excellent lithium storage performance of MnO and the good stability of carbon. Because MnO is embedded in the three-dimensional carbon networks, it can provide proper space to alleviate the volume effect during discharging and charging. The unique architecture and large surface area enable the composites to exhibit remarkable lithium storage properties with outstanding rate performance, high reversible capacity, and cycle life. The optimized sample (MnO/C-750) has excellent performance of 1067.95 mAh g−1 at 0.2 A g−1 over 200 cycles and 722.32 mAh g−1 at 1 A g−1 over 600 cycles.

Sufficient and well-distributed active sites and highly conductive carbon matrix are two important factors to achieve highly efficient electrocatalysts. In this study, we report an adjusted metal-organic frameworks (MOF)-based route for the preparation of nitrogen-doped Fe/Co bimetallic electrocatalysts. With suitable Fe/Co molar ratio (Fe/Co = 1/4.15), Co nanoparticles (NPs) with mild oxidation state and Co 3 Fe 7 alloys wrapped with thin graphene layers are embedded in an integrated and continuous carbon network. The corresponding FC@NCs-4.15 catalyst exhibits excellent oxygen reduction reaction (ORR) activity (onset potential (E onset) of 0.94 V and half-wave potential (E 1/2) of 0.84 V vs RHE) in alkaline medium, close to commercial Pt/C and superior to the other two FC@NCs. The desirable ORR performance results from the uniform distribution Co 3 Fe 7 active sites, electron density modification from Co NPs to surrounding carbon layers, hierarchical pore structure with large surface area, low carbon content, high pyridinic and graphitic N components. The FC@NCs-4.15 also displays satisfactory methanol crossover tolerance and durability. [ABSTRACT FROM AUTHOR]

Silicon-based materials with designed morphology and composite structure have received increasing interest in recent years due to the potential wide application for energy storage devices. However, these Si-based nanocomposites were usually synthesized and functionalized with other materials at a high temperature. Herein, one flocculent carbon network-twined C/Si/SiC nanocomposites were synthesized by a novel in-situ laser irradiation method using SiC targets as both a template and the source of C and Si. The fragmentation, decomposition and reshaping processes of bulk SiC to flocculent C/Si/SiC are simultaneously accomplished in one step, which can provide a more stable structure between epitaxial Si layer and C layer. What is more, due to the distinct laser-induced loose microstructure and flocculated carbon nanosheets, such nanocomposites exhibit a high specific surface area and hierarchically porous structure. Image 1 • Flocculent carbon network-twined C/Si/SiC composite structure was synthesized. • Bulk SiC were changed to flocculent carbon network-twined C/Si/SiC. • The composites were fabricated by simple in-situ laser irradiation in nature. • Such unique flocculent network structures exhibit a high specific surface area. [ABSTRACT FROM AUTHOR]

Abstract A facile carbothermal route was adopted to obtain niobium carbide nanoparticles (NPs) embedded in carbon network from Nb2O5 to study photocatalytic behavior. Optimization of synthesis parameters to obtain single phase NbC NPs has been successfully done. The phase identification, morphology and nature of carbon were determined with the help of X-ray diffraction, transmission electron microscopy (TEM) and Raman spectroscopy. X-ray photoelectron spectroscopy (XPS) suggested the presence of multiple oxidation states of Nb associated to NbC and NbCxOy centers on the surface of NPs. Due to the presence of NbCxOy on the surface of NPs, absorption under visible region of EM spectrum has been observed by UV-visible spectroscopy. Different organic dyes (RhB, MB and MO) were used to study the effect of holding time on the photocatalytic performance of as-synthesized samples. RhB dye was found to be the most sensitive organic molecule among all the considered dyes and degraded 78% in 120 min.

LiFePO4 (LFP) has been recommended as a promising cathode material due to its excellent cycle performance and high safety. However, the poor performance of low temperatures restricts the development and application of LFP cathode. Herein, the electrochemical properties of the previously synthesized LFP/C-P composite with carbon coating and phosphorus doping are discussed in the low temperature. In the low-temperature environment of − 40 °C, the first discharge-specific capacity of the LFP/C-P composite cathode at 0.1 C can reach 82.7 mAh g−1, while discharge-specific capacity of pristine commercial LFP is only 72.2 mAh g−1. To further improve the electrochemical performance of LFP/C-P at low temperatures, different charging-discharging methods were compared. It is noted that prolonging the constant voltage charging time can further improve the electrochemical performance of the cell, which increases the discharge capacity of LFP/C-P to 85.8 mAh g−1. The LFP/C-P composite cathode therefore not only ameliorates the poor electrochemical performance of LFP but provides a new way to broaden its application range. [ABSTRACT FROM AUTHOR]

Cost-effective electrocatalysts with excellent oxygen reduction reaction (ORR) activity are requisite for the commercial application fuel cells and zinc-air batteries. Herein, we prepare a series of carbon-based non-precious metal catalysts by simply carbonizing the mixture of FeCo-ZIF, melamine and soya-bean oil. The microstructure and electrochemical activity of the prepared catalysts highly depend on the adding amount of FeCo-ZIF. With proper addition, the FeCo-ZIF are transformed into Co 5.47 N and Co 0.72 Fe 0.28 alloy nanoparticles, which are embedded in the in situ formed carbon network consisted of nitrogen-doped graphene-like carbon nanosheets and interwoven carbon nanotubes. The resulted catalyst (FeCo@NCs-0.15) with considerable specific surface area and high pore volume demonstrates a superior ORR catalytic activity than commercial Pt/C with a half-wave potential (E 1/2) of 0.83 V (vs. RHE), onset potential (E onset) of 0.97 V (vs. RHE) and 4-electron dominated reaction path. The durability and methanol resistance are also better than that of commercial Pt/C in alkaline solution. This study provides an inexpensive, facile and scalable strategy to simultaneously realize non-precious metal-based active sites, nitrogen-doping, porosity and highly conductive carbon matrix in one electrocatalyst by one step. [ABSTRACT FROM AUTHOR]

Recently, lithium-ion batteries (LIBs) have been considered as an extremely important energy source for abundant smart electronic devices. Even so, lower cycle life of LIBs and capacitance performance remains rough challenges due to dramatic structure degradation. Rational structure design is highly desirable to fully improve the electrochemical performance of LIBs. Herein, a hybrid structure of carbon network adorned with nickel particles (Ni/CN) was developed. The ultra-thin interconnected CNs not only provide robust support for ultra-tiny Ni nanoparticles, but also enhance the electrical conductivity network of hybrid structure. The carbon around the Ni nanoparticles is graphitized as soft carbon with large interlayer spacing and good electrical conductivity, which benefits Li+ ion insertion/extraction. Furthermore, large specific surface area, open internal space are favorable for shorten Li+ ion diffusion channel and rapid charge transfer are favorable for accelerating Li+ ion diffusion and accommodating volume strain during the repeated lithiation/delithiation process. Benefiting from these structural and compositional advantages, the Ni/CN anode displays an ultra-stable cyclic lifespan with a specific capacity of 544.7 mAh g−1 (at 1 A g−1) even after 2000 cycles, excellent capacity retention of 121.1%. Therefore, high-energy storage and long lifespan of Ni/CN materials display a bright prospect. Image 1 The as-fabricated Ni/CN exhibits distinctive structure and possible mechanism for lithium ion storage. • We designed a 3D carbon network structure decorated with nickel nanoparticles. • Synergistic effect between nickel and carbon network improves capacity and stability. • It presents an ultrahigh cyclic duration (121.1% retention after 2000 cycles). [ABSTRACT FROM AUTHOR]

Through this work, a carbon network/aluminum matrix porous composite material was analyzed for its susceptibility to material degradation in sulfuric acid and seawater corrosive media. Simple potentiodynamic electrochemical testing was implemented, and from polarization curves, the Tafel coefficients and exchange current densities were obtained for a comparative analysis. The pseudo exchange current densities for corrosion of the composite material were compared to those found for Al 1235 and 6061-T6. By relating the pseudo icorr of these materials in each environment, an understanding regarding the relative propensity to corrosion was determined. According to the recovered data, the composite had the lowest pseudo icorr in all corrosion systems and was consequently inferred the least likely to corrode. The factor that primarily contests this conclusion is the material's relatively large exposed surface area. The existence of carbon along the grain boundaries in the C/Al composite improved its corrosion behavior. Further discussion concerning the implication of βc is offered. Electrochemical impedance spectroscopic (EIS) tests were performed in the frequency range from 0.001 Hz to 100 kHz. An immersion corrosion test was conducted to calculate the corrosion rate in different environments. Morphological observation on the corrosion surface was also carried out to evaluate the corrosion product deposition on each material. [ABSTRACT FROM AUTHOR]

Abstract SnO 2 monocrystals with an average particle size of ∼10 nm have been in-situ embedded in a tridimensional carbon network (marked as SnO 2 @C) with a high loading percentage of 39.5 wt%. The synthetic mechanism of SnO 2 @C nanocomposite is discussed. The X-ray photoelectron spectroscopies demonstrate probable chemical bonding between SnO 2 nanoparticles and the carbon framework for enhanced lithium storage performance of SnO 2 @C nanocomposite as an anode material for lithium ion batteries. The SnO 2 @C anode material delivers an initial charge capacity of 844 mAh/g at 0.1 C, and can retain a specific capacity of 661 mAh/g after 700 electrochemical cycles at 1 C (1 C = 0.79 A/g), showing considerably improved cycling and high-rate performance as compared with the bare SnO 2 material. The high lithium storage capacity of SnO 2 @C anode material can be attributed to electrochemical reversibility related to the reduction of SnO to Sn and corresponding re-oxidation process, according to a reversible redox pair at 1.10/1.25 V recorded in CV cycles. The SnO 2 @C anode also reveals outstanding cycling stability at elevated temperature, resulting in a remaining capacity of 512 mAh/g after 125 cycles at 1 C and 233 mAh/g after 300 cycles at 5 C at 55 °C, respectively. TEM/HRTEM images show desirable structural integrity of cycled SnO 2 @C nanocomposite and the robustness of the carbon network, which significantly contributes to superior lithium storage performance. Graphical abstract Image 1 Highlights • SnO 2 monocrystals are in-situ embedded in a tridimensional carbon network. • SnO 2 @C nanocomposite delivers superior lithium storage performance at 55 °C. • Chemical bonding is introduced between SnO 2 nanoparticles and the carbon network. • TEM images demonstrate preserved nanostructure of cycled SnO 2 @C nanocomposite. [ABSTRACT FROM AUTHOR]

Through this work, a carbon network/aluminum matrix porous composite material was analyzed for its susceptibility to material degradation in sulfuric acid and seawater corrosive media. Simple potentiodynamic electrochemical testing was implemented, and from polarization curves, the Tafel coefficients and exchange current densities were obtained for a comparative analysis. The pseudo exchange current densities for corrosion of the composite material were compared to those found for Al 1235 and 6061-T6. By relating the pseudo icorr of these materials in each environment, an understanding regarding the relative propensity to corrosion was determined. According to the recovered data, the composite had the lowest pseudo icorr in all corrosion systems and was consequently inferred the least likely to corrode. The factor that primarily contests this conclusion is the material’s relatively large exposed surface area. The existence of carbon along the grain boundaries in the C/Al composite improved its corrosion behavior. Further discussion concerning the implication of βc is offered. Electrochemical impedance spectroscopic (EIS) tests were performed in the frequency range from 0.001 Hz to 100 kHz. An immersion corrosion test was conducted to calculate the corrosion rate in different environments. Morphological observation on the corrosion surface was also carried out to evaluate the corrosion product deposition on each material.

Abstract: The commercialized LIBs employing graphite as anodes currently suffer a series of problems from the safety, theoretical capacity (372 mAh g−1) and rate capability. Herein, self-assembly mesoporous Zn ferrite (ZnFe2O4) microsphere embedded into carbon network has been synthesized by a facile method in the presence of citric acid. The Zn ferrites as an anode material with novel structure demonstrate superior electrochemical performance, with enhanced specific reversible capacity (∼1100 mAh g−1 at the specific current of 0.05 A g−1 after 100 cycles), excellent rate capability (more than 500 mAh g−1 even at the specific current of 1.1 A g−1) and good cycleability with little fading (∼97.6% after 100 cycles). The excellent cycling performance is associated with the loose Zn ferrite microsphere with numerous mesopores embedded into the carbon network, which can accommodate the severe mechanism strains and provides good electrical contact and conductivity. The superior electrochemical performance may facilitate ZnFe2O4 to be a promising alternative anode in lithium ion battery. [Copyright &y& Elsevier]

Abstract: Uniform nanospherical Li2MnSiO4/C/graphene composites have been obtained by polyethylene glycol-600 (PEG-600) assisted solid-state reaction using spherical SiO2 as precursor, and heat treatment with the mixed carbon sources (glucose, cellulose acetate and graphene oxide). The transmission electron microscope (TEM) images show that Li2MnSiO4 nanospheres with size of 50 nm are embedded in the three-dimensional (3D) nest-like carbon network. Electrochemical measurements reveal that the composites exhibit first discharge capacity of 215.3 mAh g−1 under 0.05 C, together with a stable discharge capacity of 175 mAh g−1 after 40 cycles. The 3D carbon network and the carbon layer (amorphous carbon and graphene) are favorable for improving the electrochemical performance. [Copyright &y& Elsevier]

• Using CO 2 as the carbon source, the Si/carbon solid-phase doping is realized by introducing the active agent Mg. • The actual particle size of Si in the prepared Si-based anode material is less than 50 nm. • The three-dimensional network structure of carbon provides the most critical buffer layer for Si volume change. SiO 2 is one of the critical raw materials for preparing Si anode. The direct use of porous Si made from SiO 2 in LIBs is challenging. Although carbon cladding can improve the cycling performance of Si anode materials made from SiO 2 , the surface coating cannot address the comminution inside the material during repeated volume deformation. For the first time, we prepared an in-situ doped Si/carbon anode material that uses SiO 2 and CO 2 as Si and carbon sources and Mg as the reduction medium (Mg 2 Si + CO 2 → MgO + Si + C). The in situ embedded carbon completes the nanosizing of Si (less than50 nm) and forms a three-dimensional (3-D) carbon network that enhances electrical conductivity and acts as a buffer layer. After 500 cycles at 0.5 A g−1, the discharge specific capacity is 912 mAh g−1, and the capacity still has 1487 mAh g−1 even at 4 A g−1. The simple method of preparing Si/carbon composite material in situ provides a new idea for modifying Si-based anode material and provides a valuable reference for carbon doping. [ABSTRACT FROM AUTHOR]