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Metal–Organic Polymers (MOPs) have attracted growing attention for lithium-ion battery (LIB) applications due to their merits in orderly ionic transportation and robust structure stability in electrochemical reactions. However, they suffer from poor electronic conductivity. In this work, we apply first-principles density functional theory to explore the potential of three one-dimensional (1D) electrically conductive C6H2S4TM (TM = Fe, Co, and Ni) MOPs with the π–d conjugated coordination as anode materials for Li+ ions storage. Our theoretical results reveal that these 1D MOPs possess a superior theoretical capacity of over 748 mA h g−1. In particular, the 1D C6H2S4Ni MOP shows an exceptional theoretical specific capacity of 1110 mA h g−1 based on the three-electron transferring reaction, which significantly outperforms the traditional graphite-based anode material in LIBs. Moreover, the resonant charge transfer between Ni metal and ligand within the 1D C6H2S4Ni MOP reduces the diffusion energy barrier of the Li atoms when they migrate on the surface of the MOP. The ultrahigh theoretical specific capacity of the C6H2S4Ni MOP predicts that it can be a promising anode material for LIBs. [ABSTRACT FROM AUTHOR]

High energy and power density alkali‐ion (i.e., Li+, Na+, and K+) batteries (AIBs), especially lithium‐ion batteries (LIBs), are being ubiquitously used for both large‐ and small‐scale energy storage, and powering electric vehicles and electronics. However, the increasing LIB‐triggered fires due to thermal runaways have continued to cause significant injuries and casualties as well as enormous economic losses. For this reason, to date, great efforts have been made to create reliable fire‐safe AIBs through advanced materials design, thermal management, and fire safety characterization. In this review, the recent progress is highlighted in the battery design for better thermal stability and electrochemical performance, and state‐of‐the‐art fire safety evaluation methods. The key challenges are also presented associated with the existing materials design, thermal management, and fire safety evaluation of AIBs. Future research opportunities are also proposed for the creation of next‐generation fire‐safe batteries to ensure their reliability in practical applications. [ABSTRACT FROM AUTHOR]

The evolution of modern society demands sustainable rechargeable lithium-ion batteries (LIBs) with higher capacity and improved safety standards. High voltage Ni-rich layered transition metal oxides (i.e., LiNi 1-x-y Co x Mn y O 2 , NCM) have emerged as one of the most promising cathode materials in meeting this demand. However, the instability of Ni-rich NCMs cathodes presents challenges in large-scale commercialization. This review examines the energy storage mechanism, e.g., possible (electro)chemical reactions, occurring at the bulk and surface and degradation mechanism of the Ni-rich NCMs cathode materials. To address the challenging instability issue, we highlight recent advances and strategies for bulk and surface engineering of Ni-rich NCMs, including lattice, composition, and microstructure engineering, and electrolyte and materials interfacial engineering. By addressing degradation mechanisms and improving overall stability, this work sheds lights on the potential avenues on the commercialization of Ni-rich cathode-based high-performance LIBs. [Display omitted] • Presenting the historical development and (electro)chemical properties of high-voltage Ni-rich NCM. • Unfolding the degradation mechanism of Ni-rich NCM occurring on bulk and surface. • Proposing modification strategies in bulk and surface chemistry toward stable and high-performance Ni-rich NCM cathode materials. [ABSTRACT FROM AUTHOR]

Lithium metal is considered as an ideal substitute to low‐capacity carbon anodes for rechargeable lithium‐ion batteries (LIBs) given its ultra‐high theoretical specific capacity of 3860 mAh g−1 and the lowest electrochemical potential. However, safety issues stem from the uncontrollable formation and growth of lithium dendrites, which severely plague the practical application of the Li anode. Here, a multi‐functional protection layer, prepared by a one‐step spin‐coating of CuCl2N‐Methyl‐2‐Pyrrolidone (NMP) solution on a lithium metal surface is constructed. The as‐prepared protective layer has a variable porous morphology that consists of a conductive lithium‐copper alloy and electrochemically active CuCl, which proactively facilitates the homogeneous diffusion of Li‐ions, the elimination of random dendrite nuclei, and even distribution of charge at the Li anode surface, and subsequently the uniform deposition of Li+ ions. Under such a dynamic protection mechanism, the proposed CuCl2 modified Li electrode can stably cycle more than 1500 h at a current density of 1 mA cm−2 paired with lithium foil. Moreover, the assembled full battery achieves capacity retention of 85.6% even after 2000 cycles at a high rate of 5 C with a LiFePO4 cathode. This as‐proposed dynamic protection mechanism via the incorporation of the electrochemically active component could provide new guidance in the preparation of the safe and high‐performance lithium metal anodes. [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes (SPEs) have become increasingly attractive in solid‐state lithium‐ion batteries (SSLIBs) in recent years because of their inherent properties of flexibility, processability, and interfacial compatibility. However, the commercialization of SPEs remains challenging for flexible and high‐energy‐density LIBs. The incorporation of functional additives into SPEs could significantly improve the electrochemical and mechanical properties of SPEs and has created some historical milestones in boosting the development of SPEs. In this study, we review the roles of additives in SPEs, highlighting the working mechanisms and functionalities of the additives. The additives could afford significant advantages in boosting ionic conductivity, increasing ion transference number, improving high‐voltage stability, enhancing mechanical strength, inhibiting lithium dendrite, and reducing flammability. Moreover, the application of functional additives in high‐voltage cathodes, lithium–sulfur batteries, and flexible lithium‐ion batteries is summarized. Finally, future research perspectives are proposed to overcome the unresolved technical hurdles and critical issues in additives of SPEs, such as facile fabrication process, interfacial compatibility, investigation of the working mechanism, and special functionalities. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (C 3 N 4) is the most widely reported member of the carbon nitride family because of its large pores which serve as alkali-metal atom storage sites. However, adsorption of Li atoms into these triangular pore sites occur at a high adsorption energy (E ad) of ∼4.2 eV which surpasses the desorption energy of bulk Li (3 eV) thereby resulting in ineffective desorption. Lithium storage in C 3 N 4 occurs via an intercalation/deintercalation process therefore the inability of adsorbed Li atoms to desorb from its structure results in structural instability, poor conductivity and limited reversible capacity. Here, we show that by doping Si atoms into the pore sites of C 3 N 4 , the Li E ad can be significantly decreased to 2.51 eV. This suitable E ad enabled effective Li transport, improved charge transfer, modulated the electronic conductivity, decreased the Li diffusion barrier and boosted the lithium storage capacity to 557.7 mAh/g. These results show that Si doping is an effective way to resolve the problems associated with C 3 N 4 and to achieve superior electronic properties and lithium storage capacity. These interesting results show the potential of Si doped C 3 N 4 for lithium ion batteries and this approach can be extended to other carbon nitride structures. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: Comprehensive summary of crystalline structures and morphologies of carbon nitride-based materials (CNBMs). Density functional theory computation for the design of functional CNBMs for rechargeable battery applications. The experimental synthesis strategies of CNBMs for rechargeable battery application. Carbon nitrides (including CN, C2N, C3N, C3N4, C4N, and C5N) are a unique family of nitrogen-rich carbon materials with multiple beneficial properties in crystalline structures, morphologies, and electronic configurations. In this review, we provide a comprehensive review on these materials properties, theoretical advantages, the synthesis and modification strategies of different carbon nitride-based materials (CNBMs) and their application in existing and emerging rechargeable battery systems, such as lithium-ion batteries, sodium and potassium-ion batteries, lithium sulfur batteries, lithium oxygen batteries, lithium metal batteries, zinc-ion batteries, and solid-state batteries. The central theme of this review is to apply the theoretical and computational design to guide the experimental synthesis of CNBMs for energy storage, i.e., facilitate the application of first-principle studies and density functional theory for electrode material design, synthesis, and characterization of different CNBMs for the aforementioned rechargeable batteries. At last, we conclude with the challenges, and prospects of CNBMs, and propose future perspectives and strategies for further advancement of CNBMs for rechargeable batteries. [ABSTRACT FROM AUTHOR]

Searching new organic cathode materials to address the issues of poor cycle stability and low capacity in lithium ion batteries (LIBs) is very important and highly desirable. In this research, a 2D boroxine‐linked chemically‐active pyrene‐4,5,9,10‐tetraone (PTO) covalent organic framework (2D PPTODB COFs) was synthesized as an organic cathode material with remarkable electrochemical properties, including high electrochemical activity (four redox electrons), safe oxidation potential window (between 2.3 and 3.08 V vs. Li/Li+), superb structural/chemical stability, and strong adhesiveness. A binder‐free cathode was obtained by mixing 70 wt % PPTODB and 30 wt % carbon nanotubes (CNTs) as a conductive additive. Promoted by the fast kinetics of electrons/ions, high electrochemical activity, and effective π–π interaction between PPTODB and CNTs, LIBs with the as‐prepared cathode exhibited excellent electrochemical performance: a high specific capacity of 198 mAh g−1, a superb rate ability (the capacity at 1000 mA g−1 can reach 76 % of the corresponding value at 100 mA g−1), and a stable coulombic efficiency (≈99.6 % at the 150th cycle). This work suggests that the concept of binder‐free 2D electroactive materials could be a promising strategy to approach energy storage with high energy density. [ABSTRACT FROM AUTHOR]

Further commercial application of low‐cost NiO‐based anodes is hindered by their large volume expansion after full lithiation and relatively poor theoretical capacity. To improve these issues, transition metal (Fe, Co, or Mn)‐modified triple‐shelled NiO microspheres (TS‐NiO) are successfully synthesized by using a hard template double‐adsorption method. Among them, the Fe‐modified TS‐NiO (TS‐NFO) exhibits an extraordinary lithium storage ability with high reversible capacity and outstanding cycling stability (2061.1 mAh g−1 after 800 cycles at 0.5 A g−1), which is the highest performing nickel oxide‐based anode reported to date. The outstanding electrochemical performance of TS‐NFO can be ascribed to its unique triple‐shelled structure. The inner core of TS‐NFO is composed of NiO and is encapsulated by two outer shells which are composed of a mixture of α‐Fe2O3 and NiFe2O4, resulting in a unique hollow triple‐shelled structure (NiO@α‐Fe2O3/NiFe2O4). The void space between the triple shells leaves room for their volume changes during lithiation/delithiation, which improves the cycling stability. In addition, the introduced α‐Fe2O3/NiFe2O4 outer shells increase the energy density and reversible capacity due to a synergistically interactive effect. [ABSTRACT FROM AUTHOR]

A novel conjugated copolymer has been synthesized and employed as an organic cathode material in rechargeable lithium–ion batteries (LIBs). Due to the synergistic effects from conducting aniline and pyrene units, the resultant batteries based on the as‐obtained copolymer can deliver a promising reversible specific capacity of 113 mAh g−1 with a high voltage output of 3.2 V and a remarkable 75.2 % capacity retention after 180 cycles. Moreover, an excellent rate performance is also achieved with a fast recovery of the capacity at different current densities. [ABSTRACT FROM AUTHOR]

The poor cycling stability resulting from the large volume expansion caused by lithiation is a critical issue for Si‐based anodes. Herein, we report for the first time of a new yolk–shell structured high tap density composite made of a carbon‐coated rigid SiO2 outer shell to confine multiple Si NPs (yolks) and carbon nanotubes (CNTs) with embedded Fe2O3 nanoparticles (NPs). The high tap density achieved and superior conductivity can be attributed to the efficiently utilised inner void containing multiple Si yolks, Fe2O3 NPs, and CNTs Li+ storage materials, and the bridged spaces between the inner Si yolks and outer shell through a conductive CNTs "highway". Half cells can achieve a high area capacity of 3.6 mAh cm−2 and 95 % reversible capacity retention after 450 cycles. The full cell constructed using a Li‐rich Li2V2O5 cathode can achieve a high reversible capacity of 260 mAh g−1 after 300 cycles. [ABSTRACT FROM AUTHOR]

Silicon has demonstrated great potential as anode materials for next-generation high-energy density rechargeable lithium ion batteries. However, its poor mechanical integrity needs to be improved to achieve the required cycling stability. Nano-structured silicon has been used to prevent the mechanical failure caused by large volume expansion of silicon. Unfortunately, pristine silicon nanostructures still suffer from quick capacity decay due to several reasons, such as formation of solid electrolyte interphase, poor electrical contact and agglomeration of nanostructures. Recently, increasing attention has been paid to exploring the possibilities of hybridization with carbonaceous nanostructures to solve these problems. In this review, the recent advances in the design of carbon-silicon nanohybrid anodes and existing challenges for the development of high-performance lithium battery anodes are briefly discussed. [ABSTRACT FROM PUBLISHER]

Nanostructured semiconductors have been researched intensively for energy conversion and storage applications in recent decades. Despite of tremendous findings and achievements, the performance of the devices resulted from the nanomaterials in terms of energy conversion efficiency and storage capacity needs further improvement to become economically viable for subsequent commercialization. Hydrogenation is a simple, efficient, and cost-effective way for tailoring the electronic and morphological properties of the nanostructured materials. This work reviews a series of hydrogenated nanostructured materials was produced by the hydrogenation of a wide range of nanomaterials. These materials with improved inherent conductivity and changed characteristic lattice structure possess much enhanced performance for energy conversion application, e.g., photoelectrocatalytic production of hydrogen, and energy storage applications, e.g., lithium-ion batteries and supercapacitors. The hydrogenation mechanisms as well as resultant properties responsible for the efficiency improvement are explored in details. This work provides guidance for researchers to use the hydrogenation technology to design functional materials. [ABSTRACT FROM AUTHOR]

Highlights from the article: Lithium Ion Batteries: A Hollow-Shell Structured V2O5 Electrode-Based Symmetric Full Li-Ion Battery with Highest Capacity (Adv. Keywords: full cell; lithium-ion batteries; multi-hollow-shell; symmetric batteries; V2O5 V2O5, full cell, symmetric batteries, lithium-ion batteries, multi-hollow-shell.

Aluminum is one of the promising alternative anode materials due to its high specific capacity. However, some critical problems seriously limit its practical applications, such as the low coulombic efficiency and poor cycle performance resulting from the huge volume change during cycling. Herein, a novel poly(furfuryl alcohol)/carbon black binder composite is coated on the surface of aluminum foil as a robust and conductive protective layer to maintain the integrity of the hybrid aluminum anode. The results show that 150 cycles under the preset cutoff capacity loading of 400 mA h g−1 are obtained and exhibit obvious advantages over a bare aluminum anode, which will crack after just 25 cycles. For full‐cell testing paired with a LiFePO4 cathode, the cell using the hybrid aluminum anode has a better capacity retention against the unprotected aluminum anode. [ABSTRACT FROM AUTHOR]

In article number 1802645, Zhan Lin, Jun Lu and co‐workers propose a universal strategy for interweaving hard and soft polymers to construct 3D network binders to enable high areal capacities with excellent cyclability in lithium‐ion batteries. Elastic modules accommodate the volume variation of Si particles while stiff modules offer mechanically strong electrode frameworks. This strategy can provide a new principle in designing robust binder for high‐energy‐density lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Si anodes suffer an inherent volume expansion problem. The consensus is that hydrogen bonds in these anodes are preferentially constructed between the binder and Si powder for enhanced adhesion and thus can improve cycling performance. There has been little research done in the field of understanding the contribution of the binder's mechanical properties to performance. Herein, a simple but effective strategy is proposed, combining hard/soft polymer systems, to exploit a robust binder with a 3D interpenetrating binding network (3D‐IBN) via an in situ polymerization. The 3D‐IBN structure is constructed by interweaving a hard poly(furfuryl alcohol) as the skeleton with a soft polyvinyl alcohol (PVA) as the filler, buffering the dramatic volume change of the Si anode. The resulting Si anode delivers an areal capacity of >10 mAh cm−2 and enables an energy density of >300 Wh kg−1 in a full lithium‐ion battery (LIB) cell. The component of the interweaving binder can be switched to other polymers, such as replacing PVA by thermoplastic polyurethane and styrene butadiene styrene. Such a strategy is also effective for other high‐capacity electroactive materials, e.g., Fe2O3 and Sn. This finding offers an alternative approach in designing high‐areal‐capacity electrodes through combined hard and soft polymer binders for high‐energy‐density LIBs. A universal strategy, i.e. interweaving hard and soft polymers to construct 3D network binder, is proposed to enable high areal capacities with excellent cyclability in lithium‐ion batteries. Elastic modules accommodate the volume variation of Si particles while stiff modules offer mechanically strong electrode frameworks. This strategy can provide a new principle in designing robust binder for high‐energy‐density lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride nanosheet (i.e., g‐C3N4) is identified as a suitable graphene analogue due to its high theoretical capacity, wider and vacant structure, and easy synthesis method. Currently, g‐C3N4 nanosheet has limited application in lithium‐ion batteries (LIBs) which is mainly due to the lack of effective intercalation/deintercalation reaction sites, the high binding energy of the Li to the nanosheet, and insufficient conductivity and stability. Density functional theory calculation predicts that the edges of g‐C3N4 fibre have a suitable adsorption energy and bestow a balanced adsorption force and desorption freedom to Li. In order to verify this prediction, g‐C3N4 nanofibre is synthesized with the edges and pores, as well as higher pyridinic nitrogen content, using a simple polymerization/polycondensation method. The as‐prepared g‐C3N4 fibre delivers a remarkable specific capacity of 181.7 mAh g−1, as well as extraordinary stability and power density. At a high rate of 10C, the g‐C3N4 fibre still has a specific capacity of 138.6 mAh g−1 even after 5000 cycles, being the best‐performing g‐C3N4 electrode so far in literature. This work is exemplary in combining theoretical computing and experimental techniques in designing the next generation of electroactive materials for LIBs. A g‐C3N4 fibre structure with edges and low graphitic nitrogen content is developed as an anode material for lithium‐ion batteries. The g‐C3N4 fibre structure delivered an ultrahigh specific capacity of 181.7 mAh g−1 after 200 cycles at 0.5 C and 138.6 mAh g−1 at 10C with an exceptional long life of 5000 cycles. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) are emerging as an inexpensive and more sustainable alternative to lithium-ion batteries in the energy storage market. To advance their commercialization, one major scientific undertaking is to develop low-cost, reliable anode materials from abundant resources, like the success of graphite in the lithium-ion batteries. However, graphite is chemically inactive in storing sodium ions and, to render it viable in sodium-ion batteries, additional modification of graphite is required. Herein, we demonstrate a green and facile method to prepare cost-effective and stable graphitic SIB anodes. The modification process started with the electrochemical oxidation of expanded graphite to widen the interlayer and functionalize graphite layers, followed by a fast (20 min) thermal treatment at 150 °C to achieve controlled deoxygenation. The thermally processed electrochemical graphite oxide could provide a high reversible capacity of 268 mAh g−1 at 100 mA g−1 and 163 mAh g−1 at 500 mA g−1 as well as low fading in capacity (in average 0.0198% loss per cycle) over 2000 cycles. The electrochemical route eliminates the need for the harsh chemical oxidation of graphite, offering a promising approach for industrial production of low-cost anodes for sodium-ion batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

Ferric oxide has demonstrated as a promising anode candidate for lithium ion batteries (LIBs) due to large charge storage capacity, but its high cost, low Coulombic efficiency, and unstable solid-electrolyte interphase remain to be a technical challenge. Here, we report a flexible interleaved hybrid in which Fe 2 O 3 nanoparticles were encapsulated by graphene oxide layers (Fe 2 O 3 /GO) using facile freeze-drying approach as anode for LIBs. Within this flexible interleaved structure, GO layers act as flexible but mechanically strong buffer to accommodate volume expansion and reduce associated stress in Fe 2 O 3 nanoparticles, thereby maintaining mechanical integrity and increasing the cycling life of batteries. With the synergistic effects from Fe 2 O 3 and GO, this hybrid not only promotes fast mass transfer and shortens the diffusion path of the Li ions but also forms a stable solid electrolyte interface, contributing improved Coulombic efficiency in the first few cycles. The Fe 2 O 3 /GO hybrid as anode for LIBs exhibited a reversible specific capacity of ca. 890 mAh g −1 after 50 cycles at 1 C (1005 mA g −1 ) and 405 mAh g −1 after 1000 cycles at 10 C rate. Furthermore, a full-cell battery with a LiFePO 4 cathode also showed high Coulombic efficiency and good capacity retention capability. Mechanical properties and impedance spectroscopy tests were performed to confirm the mechanism in superior rate and electrochemical stability. The conclusions are considered to be very useful for design of Li batteries with improved mechanical performance. [ABSTRACT FROM AUTHOR]

The high rate applications such as electric vehicles of the traditional lithium ion batteries (LIBs) are commonly limited by their insufficient electron conductivity and slow mass transport of lithium ions in bulk electrode materials. In order to address these issues, in this work, a simple and up-scalable wet-mechanochemical (wet-ball milling) route has been developed for fabrication of amorphous porous TiO 2 @nitrogen doped graphene (TiO 2 @N-G) nanocomposites. The amorphous phase, unique porous structure of TiO 2 and the surface defects from nitrogen doping to graphene planes have incurred surface controlled reactions, contributing pseudocapacitance to the total capacity of the battery. It plays a dominant role in producing outstanding high rate electrochemical performance, e.g., 182.7 mAh/g (at 3.36 A/g) after 100 cycles. The design and synthesis of electrode materials with enhanced conductivity and surface pseudocapacitance can be a promising way for high rate LIBs. [ABSTRACT FROM AUTHOR]

An environmentally benign, highlyconductive, and mechanicallystrong binder system can overcome the dilemma of low conductivityand insufficient mechanical stability of the electrodes to achievehigh performance lithium ion batteries (LIBs) at a low cost and ina sustainable way. In this work, the naturally occurring binder sodiumalginate (SA) is functionalized with 3,4-propylenedioxythiophene-2,5-dicarboxylicacid (ProDOT) via a one-step esterification reaction in a cyclohexane/dodecylbenzenesulfonic acid (DBSA)/water microemulsion system, resultingin a multifunctional polymer binder, that is, SA-PProDOT. With thesynergetic effects of the functional groups (e.g., carboxyl, hydroxyl,and ester groups), the resultant SA-PProDOT polymer not only maintainsthe outstanding binding capabilities of sodium alginate but also enhancesthe mechanical integrity and lithium ion diffusion coefficient inthe LiFePO4(LFP) electrode during the operation of thebatteries. Because of the conjugated network of the PProDOT and thelithium doping under the battery environment, the SA-PProDOT becomesconductive and matches the conductivity needed for LiFePO4LIBs. Without the need of conductive additives such as carbon black,the resultant batteries have achieved the theoretical specific capacityof LiFePO4cathode (ca. 170 mAh/g) at C/10 and ca. 120mAh/g at 1C for more than 400 cycles. [ABSTRACT FROM AUTHOR]

Abstract: Graphene nanosheets are synthesized by a novel facile method involving freeze-drying technology and thermal reduction. The microstructure and morphologies are characterized by X-ray diffraction, Brunauer–Emmett–Teller measurements, Fourier transform infrared spectroscopy, and high resolution transmission electron microscope. The results indicate that graphene nanosheets with high specific surface area (358.3 m2 g−1) and increased interlayer distance (0.385 nm) are successfully obtained through the freeze-drying process. The electrochemical performances are evaluated by using coin-type cells versus lithium. A high initial reversible capacity of 1132.9 mAh g−1 is obtained at a current density of 100 mA g−1. More importantly, even after 300 cycles at a high current density of 1000 mA g−1, a stable specific capacity of 556.9 mAh g−1 can be achieved, suggesting the graphene nanosheets exhibit superior cycle stability. The fascinating electrochemical performance could be ascribed to the high specific surface area and the increased layer distance between the graphene nanosheets. [Copyright &y& Elsevier]

Abstract: Carbon nanotube (CNT) and TiO2 nanofibre composite films are prepared and used as anode materials for lithium ion batteries (LIBs) without the use of binders and conventional copper current collector. The preliminary experimental results from X-ray diffraction, scanning electron microscopy and transmission electron microscopy suggest that the TiO2 nanofibres were well-dispersed and interwoven by the CNTs, forming freestanding, bendable and light weighted composite. In comparison with TiO2 nanofibre based LIBs, the CNTs could significantly improve the battery performance due to their high conductivity property and 3D network morphology. In both 1–3V and 0.01–3V testing voltage ranges, the as-prepared composites show excellent reversible capacity and capacity retention. The superior lithium storage capacity of the CNT/TiO2 composite was mainly attributed to dual functions of the CNTs – the CNTs not only provide conductive networks to assist the electron transfer but also facilitate lithium ion diffusion between the electrolyte and the TiO2 active materials by preventing agglomeration of TiO2 nanofibres. This work demonstrates that the CNT–TiO2 composite film could be one type of potential electrode material for large-scale LIB applications. [Copyright &y& Elsevier]

Abstract: TiO2/nitrogen-doped graphene nanocomposite was synthesized by a facile gas/liquid interface reaction. The structure and morphology of the sample were analyzed by X-ray diffraction analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The results indicate that nitrogen atoms were successfully doped into graphene sheets. The TiO2 nanoparticles (8–13nm in size) were homogenously anchored on the nitrogen-doped graphene sheets through gas/liquid interface reaction. The as-prepared TiO2/nitrogen-doped graphene nanocomposite shows a better electrochemical performance than the TiO2/graphene nanocomposite and the bare TiO2 nanoparticles. TiO2/nitrogen-doped graphene nanocomposite exhibits excellent cycling stability and shows high capacity of 136mAhg−1 (at a current density of 1000mAg−1) after 80cycles. More importantly, a high reversible capacity of 109mAhg−1 can still be obtained even at a super high current density of 5000mAg−1. The superior electrochemical performance is attributed to the good electronic conductivity introduced by the nitrogen-doped graphene sheets and the positive synergistic effect between nitrogen-doped graphene sheets and TiO2 nanoparticles. [Copyright &y& Elsevier]

In this work, cross-linked dextrin as a low-cost and aqueous binder has been prepared for silicon (Si) based anodes in Li-ion batteries. A 3D network is achieved by the aldolization between the hydroxyl groups in dextrin and the aldehyde groups in glutaraldehyde. This inter-waving structure demonstrates good mechanical property and can mitigate the volume variation of Si anodes during cycling, resulting in a better electrochemical performance than that with PVDF, CMC and pristine dextrin binders. The initial capacity is 3276 mAh g−1 with Coulombic efficiency (CE) of 88.79% and only drops to above 1000 mAh g−1 after 150 cycles under 0.1C. Adding 20 wt% FEC in the electrolyte, the cycling performance is further improved to about 1700 mAh g−1 after 150 cycles under 0.1C, and over 1000 mAh g−1 after 150 cycles under 0.5C. Therefore, the cross-linked dextrin is considered to be a promising binder for Si based electrodes, with potential for other anodes as well. Image 1 • Cross-linked dextrin is successfully prepared as a low-cost and aqueous binder. • The 3D inter-waving structure can mitigate the volume variation of Si anodes. • Better electrochemical performance is achieved as compared to conventional binders. [ABSTRACT FROM AUTHOR]