Flexible Li-ion Batteries Research Articles

Ultraviolet-cured heat-resistant and stretchable gel polymer electrolytes for flexible and safe semi-solid lithium-ion batteries

Lithium-ion (Li-ion) batteries assembled with gel polymer electrolytes (GPEs) are predicted to increase battery energy density while maintaining battery safety. In this work, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is successfully used as a polymer matrix to prepare a new kind of GPE (PHHNT) by ultraviolet (UV) curing technology. The polymer network structure formed by photopolymerization technology significantly enhances the tensile properties of the electrolyte. Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) improves the concentration and transport efficiency of lithium ions in the electrolyte as well as the ionic conductivity (1.22 × 10−3 S cm−1) of the GPEs. In addition, the unique tubular structure of the halloysite nanotube (HNT) and the opposite charges carried by the inner and outer surfaces provide additional channels for the lithium salt and facilitate its dissociation. This enhances the expedited movement of Li+ inside the electrolyte, while simultaneously improving the electrochemical and thermal durability of the electrolyte. The assembled LiFePO4 (LFP)/PHHNT/Li battery has an initial discharge-specific capacity of 140.5 mAhg−1 at a current density of 0.5C, showing a high capacity retention rate of 89 % after 120 cycles. The design of this composite material significantly improves the overall performance of the electrolyte and is more suitable for flexible and safe solid-state Li-ion batteries.

3D-printed topological-structured electrodes with exceptional mechanical properties for high-performance flexible Li-ion batteries

A vital aspect in advancing flexible batteries is the development of flexible electrodes capable of enduring repeated stretching while upholding satisfactory electrochemical performance. Thus, adopting a systematic and efficient approach to structural design and fabrication becomes imperative. In this study, we introduce an optimal structural design achieved through topology optimization and fabricate flexible electrodes via 3D printing, representing a departure from traditional design and manufacture methodologies in the development of flexible electrodes for batteries. Our research underscores the impressive mechanical strength of these topologically-structured electrodes (TSEs), validated through rigorous finite element analysis (FEA) and tensile strength testing. The results of both the stretch deformation and twist deformation analysis on the TSEs and the conventional mesh-structured electrodes (MSEs) show that the peak strain and stress of TSEs are much lower than those of MSEs. Notably, even under 50 % stretching, the TSEs maintain structural integrity, contrasting sharply with conventional mesh-structured electrodes (MSEs) and flat film electrodes which often crack under similar conditions. Moreover, after enduring 50 cycles of stretching, the TSEs retain an outstanding 98 % of their original capacity, surpassing MSEs which retain only 80 % of their capacity. These findings highlight the significant potential of topologically designed flexible electrodes, offering promising avenues for the development of stretchable and flexible energy storage devices such as wearable tech and bio-integrated electronics.

Failure Modes of Flexible LiCoO2 Cathodes Incorporating Polyvinylidene Fluoride Binders with Different Molecular Weights.

Understanding the mechanical failure modes of lithium-ion battery [Li-ion batteries (LIBs)] electrodes is exceptionally important for enabling high specific energy and flexible LIB technologies. In this work, the failure modes of lithium cobalt oxide (LCO) cathodes under repeated bending and the role of the polymer binder in improving the mechanical durability of the LCO electrodes for use in flexible LIBs are investigated. Mechanical and electrochemical evaluations of LCO electrodes (areal capacity of ≥2.5 mA h cm-2) employing poly(vinylidene fluoride) (PVDF) binder were carried out, followed by extensive optical and electron microscopies. We find that the molecular weight (MW) of the PVDF significantly influenced the surface and bulk microstructure of the LCO electrodes, particularly the distribution of carbon additive and binder, which plays a crucial role in affecting the mechanical and electrochemical properties of the electrodes. Multiple mechanical failure modes (e.g., surface scratches and microcracks) observed in the LCO electrodes subjected to repeated bending originated from the use of low MW PVDF; these failure modes were successfully mitigated by using a high MW PVDF. Remarkably, the optimized flexible LCO electrode incorporating high MW PVDF showed comparable discharge capacity retention during galvanostatic cycling after repeated bending (7000 cycles at 50 mm bending diameter) to electrodes not subjected to the repeated bending. This study highlights the importance of carrying out a comprehensive investigation of the failure mechanisms in flexible electrodes, which identified the pivotal role of the PVDF MW in the electrode microstructure and its effects on the electrode resilience to failure during repeated bending.

A three-dimensional printed Si/rGO anode for flexible Li-ion batteries

A 3D-printed Si/rGO anode with a porous grid-like structure was well designed and synthesized and exhibits an excellent electrochemical performance in flexible lithium-ion batteries.

SU8 polymer derived high capacity and performance anode material for secondary and flexible Li-ion batteries: Experimental and first principle study

This study provides a novel and sustainable protocol for the synthesis of SU8 polymer-based pattern, un-pattern carbon nanofibers (CNF) using an electrospinning process followed by a photolithography technique. Scanning electron microscopy (SEM) analysis of pattern, un-pattern CNFs shows that the average diameter of CNF is within the range of 60–140 nm. Transmission electron microscopy (TEM) studies disclose the average size of CNF exists within the range of 40–150 nm. The first-principle calculations predict that the gravimetric energy and power densities of Li/CNF half cells are 26.96 kW h g−1 and 26.96 kW g−1, respectively. The corresponding theoretical volumetric energy and power densities are 0.07 W h cm−3 and 0.07 W cm−3, respectively. Electrochemical analysis demonstrates the initial discharge capacities of pattern, un-pattern Li/CNF half cells at 100 mA g−1 are 3450 and 2429.8 mA h g−1, respectively. The gravimetric energy density of pattern, un-pattern Li/CNF half cells are within the range of 1800–1366.76 W h kg−1, and subsequent power densities are in the span of 519.63–434.22 kW g−1. The theoretical gravimetric energy and power densities of CNF/LiMn0.33Ni0.33Co0.33 (LMNC) full cells are 2.9 kWh kg−1 and ∼ 2.9 kW kg−1, respectively. Their theoretical volumetric energy and power densities are 1.96 W h cm−3 and 1.96 W cm−3, respectively. Electrochemical analysis discloses that the gravimetric energy and power densities of pattern CNF/LMNC full cells are in the range of 43.18–42.4 kW h kg−1 and 51.82–50.90 kW kg−1, respectively. The gravimetric energy and power densities of un-pattern CNF/LMNC full cells are 42.07–41.59 W h kg−1 and 50.48–49.92 kW kg−1, respectively.

Quantum dot-derived carbon nanopocket-confined Co3O4 within mesoporous carbon nanofiber for Cu-free anode of flexible Li-ion batteries

Cu-free flexible anodes, which are promising alternatives to the conventional anode type, have received global attention owing to their advantages, such as flexible deformability and elimination of interfacial trouble between active materials and current collector. However, these Cu-free anodes suffer from low specific capacitance and poor mechanical properties. To overcome these issues, we introduced carbon quantum dots (CQDs) as inner structure modification agents and Co3O4 nanoparticles within a mesoporous carbon nanofibers (CNF). Herein, we report a novel strategy for developing highly flexible Cu-free anode using the mesoporous CNF structure together with quantum dot-induced carbon nanopocket effect. During the carbonization process, the surface functional groups of the CQDs decomposed, which led to the formation of a carbon nanopocket. This carbon nanopocket effectively suppressed the particle growth of cobalt oxide. Moreover, mesoporous surface morphology was successfully developed using a post-oxidation process. The resultant Co3O4/CQD-PCNF flexible anode showed superior anode performances, including the high specific capacity of 783.43 and 227.59 mAh/g at a current density of 100 and 2,000 mA/g, respectively, with an excellent high-rate capability of 79.6% after 1,000 cycles of intense flexible test. Therefore, the Co3O4/CQD-PCNF Cu-free anode can provide a new direction to electrode modification strategies for achieving free-standing anode for highly flexible Li-ion batteries.

Thermal Expansion and Thermal Conductivity of Ni/Graphene Composite: Molecular Dynamics Simulation.

In the present work, the thermal conductivity and thermal expansion coefficients of a new morphology of Ni/graphene composites are studied by molecular dynamics. The matrix of the considered composite is crumpled graphene, which is composed of crumpled graphene flakes of 2-4 nm size connected by van der Waals force. Pores of the crumpled graphene matrix were filled with small Ni nanoparticles. Three composite structures with different sizes of Ni nanoparticles (or different Ni content-8, 16, and 24 at.% Ni) were considered. The thermal conductivity of Ni/graphene composite was associated with the formation of a crumpled graphene structure (with a high density of wrinkles) during the composite fabrication and with the formation of a contact boundary between the Ni and graphene network. It was found that, the greater the Ni content in the composite, the higher the thermal conductivity. For example, at 300 K, λ = 40 W/(mK) for 8 at.% Ni, λ = 50 W/(mK) for 16 at.% Ni, and λ = 60 W/(mK) for 24 at.% Ni. However, it was shown that thermal conductivity slightly depends on the temperature in a range between 100 and 600 K. The increase in the thermal expansion coefficient from 5 × 10-6 K-1, with an increase in the Ni content, to 8 × 10-6 K-1 is explained by the fact that pure Ni has high thermal conductivity. The results obtained on thermal properties combined with the high mechanical properties of Ni/graphene composites allow us to predict its application for the fabrication of new flexible electronics, supercapacitors, and Li-ion batteries.

First-principles investigation on structural and optoelectronic properties of buckled SnO monolayer for effective solar energy scavenging

Two-dimensional (2D) materials have gathered considerable attention for next-generation optoelectronic devices owing to their intriguing optical and electronic properties. The semiconductor SnO has shown potential for flexible electronics, optoelectronics, gas sensing, and Li-ion battery applications due to its indirect bandgap, and high carrier mobility. In the present work, we investigate the physical properties of a buckled tin oxide (SnO) monolayer using density functional theory (DFT) calculations. The structural analysis reveals that buckled SnO monolayer is energetically stable and exhibits the hexagonal crystal structure. Phonon dispersion analysis depicts the dynamical stability of the buckled SnO monolayer and obtained the quadratic behavior of flexural acoustic modes (ZA) near the zone center. Further, the electronic property calculation shows that the buckled SnO is an indirect semiconductor with a bandgap of 1.71 eV and the transparent behavior of the material is disclosed by analyzing the optical parameters. Moreover, the computed solar power conversion efficiency of 16.76% for buckled SnO monolayer demonstrates the potential as a light absorber in the field of solar energy scavenging.

Reliability of State-of-Health of the Flexible Li-Ion Batteries Under Various Flexing Conditions and Calendar Aging

Abstract Due to the necessity for flexibility without compromising the Li-ion battery (LIB) state of health (SOH), LIB is a critical challenge for flexible hybrid electronic (FHE) devices. A thin form factor-based LIB with a thickness of less than 1 mm is regarded as the candidate material to suit such demands since it can be folded, bent, and twisted with minimal performance loss. Furthermore, LIB has high specific power (W/Kg) and specific energy (Wh/Kg), as well as a smaller memory effect, making it more appealing for wearable applications. While much research has been done on the chemo-physical effects of repeated charging and discharging LIB, such as solid electrolyte interphase (SEI) development, material deterioration, and so on, but such impacts owing to repeated flexure LIB have not been much studied. The deterioration of the reliability of thin-flexible power sources was investigated in this work under twist, flexing, and flex-to-install to simulate stresses of daily motions of the human body by utilizing motion-control setups in a lab setting. Furthermore, an AI-based regression model has been developed to forecast the SOH of the battery based on many variables such as physical, atmospheric, and chemo-mechanical experimental circumstances that may be difficult to address by manpower. Based on the various variables and their interactions, the generated models are expected to be used to predict battery life and assess the acceleration factors between test circumstances and usage conditions for a range of test scenarios.

Protein-assisted bendable Cu-free anode: Hydroxy-functionalized mesoporous carbon matrix for flexible Li-ion batteries

Several approaches have been proposed for development of a current collector-free bendable energy storage electrode for flexible lithium-ion battery applications, such as construction of a hybrid composite structure and introduction of a simple synthesis procedure. However, a more fundamental strategy is required to achieve a highly bendable electrode using carbonaceous materials. We report a novel strategy for development of a protein-assisted bendable Cu-free anode using a hydroxy-functionalized mesoporous carbon nanofiber (CNF) matrix. Zinc oxide nanoparticles and glutamic acid were used as modification agents during the preparation of CNFs and mesoporous CNF structure with N dopants and rich hydroxy groups (Glu-PCNF). The resultant Glu-PCNF electrode exhibited competitive Li-ion storage capabilities, such as a high specific capacity of 469.87 mAh/g at a current density of 100 mA/g and fast energy storage (113.6 mAh/g at 2,000 mA/g). Moreover, the Glu-PCNF electrode maintained its energy storage performance after 1,000 cycles of bending, which demonstrates its high bendability. Therefore, the Cu-free Glu-PCNF electrode, with a high bendability and competitive energy storage performance, can accelerate the implementation of next-generation electronic devices with wearable and flexible functions.

Sb Nanoparticles Embedded in the N-Doped Carbon Fibers as Binder-Free Anode for Flexible Li-Ion Batteries.

Antimony (Sb) is considered a promising anode for Li-ion batteries (LIBs) because of its high theoretical specific capacity and safe Li-ion insertion potential; however, the LIBs suffer from dramatic volume variation. The volume expansion results in unstable electrode/electrolyte interphase and active material exfoliation during lithiation and delithiation processes. Designing flexible free-standing electrodes can effectively inhibit the exfoliation of the electrode materials from the current collector. However, the generally adopted methods for preparing flexible free-standing electrodes are complex and high cost. To address these issues, we report the synthesis of a unique Sb nanoparticle@N-doped porous carbon fiber structure as a free-standing electrode via an electrospinning method and surface passivation. Such a hierarchical structure possesses a robust framework with rich voids and a stable solid electrolyte interphase (SEI) film, which can well accommodate the mechanical strain and avoid electrode cracks and pulverization during lithiation/delithiation processes. When evaluated as an anode for LIBs, the as-prepared nanoarchitectures exhibited a high initial reversible capacity (675 mAh g−1) and good cyclability (480 mAh g−1 after 300 cycles at a current density of 400 mA g−1), along with a superior rate capability (420 mA h g−1 at 1 A g−1). This work could offer a simple, effective, and efficient approach to improve flexible and free-standing alloy-based anode materials for high performance Li-ion batteries.

Prospective life cycle assessment of a flexible all-organic battery

Strong interest from researchers and industry is accelerating development of flexible energy storage technologies for future flexible devices. It is critical to consider the environmental perspective in early development of new emerging technologies. In this study, cradle-to-factory gate prospective life cycle assessment (LCA) was performed on production of an all-organic battery with conductive redox polymers as electrode material. To gain a better understanding of the environmental performance of the all-organic battery, a flexible lithium-ion (Li-ion) battery with lithium titanate oxide and lithium cobalt oxide as electrode active materials was modeled as reference. Main environmental impacts of the all-organic battery were attributable to anode and cathode production, with electrode backbones being the main contributors. Solvents, catalysts, waste treatment, energy, and bromine were key individual contributors. Comparison with the flexible Li-ion battery indicated inferior environmental performance of the all-organic battery due to its relatively low specific energy (Wh/kg) and large amount of materials needed for production of its electrode backbones. Sensitivity analysis showed that changing scaling-up parameters and the production route of 3,4-ethylenedioxythiophene (a precursor of electrode backbones) strongly influenced the results. In order to lower the environmental impacts of the all-organic battery, future research should focus on designing a short production chain with lower material inputs of electrode backbones, increasing battery cycle life, and improving the specific energy of the battery. In addition, relevant recommendations were provided for prospective LCAs of upscaled systems.

Correction to “Confining Nano-GeS2 in Cross-linked Porous Carbon Networks for High-Performance and Flexible Li-Ion Battery Anodes”

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to “Confining Nano-GeS2 in Cross-linked Porous Carbon Networks for High-Performance and Flexible Li-Ion Battery Anodes”Dong FengDong FengMore by Dong Fenghttps://orcid.org/0000-0002-8429-9024, Qi LiuQi LiuMore by Qi Liu, Zhongming LiZhongming LiMore by Zhongming Li, and Tianbiao Zeng*Tianbiao ZengMore by Tianbiao Zenghttps://orcid.org/0000-0002-7841-1841Cite this: ACS Appl. Energy Mater. 2022, 5, 7, 9225–9226Publication Date (Web):July 8, 2022Publication History Published online8 July 2022Published inissue 25 July 2022https://doi.org/10.1021/acsaem.2c01892Copyright © 2022 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views268Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (3 MB) Get e-Alerts Get e-Alerts

3D N-doped Li4Ti5O12 nanoribbon networks self-supported on Ti foils as advanced anode for high-performance flexible lithium-ion batteries

A novel three dimensional (3D) N-doped Li 4 Ti 5 O 12 (LTO) nanoribbon (N-LTONR) network electrode is synthesized by hydrothermal process and subsequent gas-solid reaction. The presence of self-doped Ti 3+ and oxygen vacancies in LTO lattice further enhances the intrinsic conductivity. The thin nanoribbons (70 nm in width and 20 nm in thickness) are twisted and intertwined to form a 3D conductive network, and can be directly served as flexible electrode for Li ion batteries (LIB) without using any binder and conductive additives. The optimized N-LTONR electrode exhibits excellent high-rate capability, low-temperature performance and cycle stability. It delivers a areal capacity of 0.26 mAh cm −2 at a high current density of 10 mA cm −2 , and has a capacity retention rate of 85.2% after 1000 cycles at 3 mA cm −2 . It also displays excellent low-temperature adaptability and retains 78.3% room temperature-capacity even under − 30 °C, exhibits a low capacity loss (2%) after 100 cycles at 1 mA cm −2 under − 20 °C. In addition, the 3D nanoribbon network electrode possesses good flexibility and has promising potential to be used for flexible and bendable LIBs. • Novel 3D Li 4 Ti 5 O 12 networks consisting of nanoribbons are fabricated on flexible Ti foils. • The as-synthesized 3D Li 4 Ti 5 O 12 nanoribbon networks can be directly used as flexible electrode for high-performance LIBs. • It exhibits much improved high-rate capacity and low-temperature adaptability.

Silicon nanowire growth on carbon cloth for flexible Li-ion battery anodes

Binder and conductive additive-free Si nanowires (NWs) grown directly on the current collector have shown great potential as next generation Li-ion battery anodes. However, low active material mass loadings and consequentially low areal capacities have remained a challenge in their development. Herein, we report the high-density growth of Si NWs on carbon cloth (CC) for use as Li-ion battery anodes. The NW growth reactions were carried out using a modified, glassware-based solvent vapor growth (SVG) process. Optimized growth conditions were applied to CC substrates to generate flexible Si NW anodes for Li-ion batteries. Battery testing revealed high areal charge and discharge capacities (>2 mAh/cm2) compared to Si NWs grown on stainless steel (SS) substrates (∼0.3 mAh/cm2) and stable long-term cycling with 80% capacity retention after 200 cycles. The findings reported herein represent a significant advancement in the field in terms of achievable areal capacity enabled by a low-cost glassware-based system.

Spherical shaped LiCo0.5Mn0.5PO4-carbon composite as high voltage cathode material for conventional and flexible Li-ion batteries

A unique approach of Co-doping at the Mn site was used to prepare spherical shaped LiMn0.5Co0.5PO4@C (LMCP@C) nanoparticles by supercritical fluid hydrothermal method. The high-resolution transmission electron microscopy (HR-TEM) study of LMCP@C nano-particles explores that the average diameter of nanospheres is in the range of 7–50 nm. XPS analysis reveals that the Mn/Co-ion exists in the divalent oxidation state. First-principle calculations explore that Co doping increases the operating voltage, specific capacity, gravimetrical energy, and power density. The corresponding theoretical values are 5.23 V, 169.1 mA h g−1, 85.164 kW h kg−1, and 85.164 kW kg−1. At the same time, the theoretical volumetric energy and power densities are 8.008 kWh cm−3 and 8.008 kW cm−3. It also reveals that Co-doping enhances the bulk modulus (∼87 GPa), shear modulus (∼92.5 GPa), and Poisson ratio (0.107). The electrochemical analysis of secondary Li-ion batteries (LIBs) explores that the initial discharge capacities at 0.1 and 100 C are 156.5, and 80 mA h g−1, gravimetrical energy, and power densities are within the range of 591.3–312 W h kg−1 and 312.2 kW kg−1, respectively. All-solid-state thin and flexible LIBs have the initial discharge capacities under different bending states at 0.1 C within the range of 141 - 140 mA h g−1. Volumetric power and energy densities are within the limit of 6.575–6.30 W cm−3 and 0.6575–0.631 W h cm−3, respectively.

High-performance, flexible, binder-free silicon–carbon anode for lithium storage applications

The development of flexible Li-ion batteries (LiBs) is important for applications in wearable devices, display systems, intelligent communication, and other electronics fields. Herein, we report a flexible, binder-free, silicon@silica@carbon nanofiber (Si@SiO2@CNF) anode fabricated by a scalable electrospinning method and a novel “pre-oxidation–slicing–carbonization” process. Si nanoparticles (Si NPs) uniformly dispersed within the CNFs were coated with layers of SiO2, leading to the formation of core–shell-structured silicon@silica (Si@SiO2). Due to the introduction of the SiO2 coating, aggregation of the Si NPs was effectively inhibited, and the change in volume of the Si NPs could be confined within the CNFs during cycling, resulting in enhanced structural and cycling stability. Furthermore, the interconnected conductive CNFs further increased the overall conductivity, leading to improved rate performance. More importantly, the novel “pre-oxidation–slicing–carbonization” process ensures the integrity of the edge of the electrode film. The fiber film obtained by electrospinning can be used directly as a freestanding, binder-free anode material, which significantly simplifies the fabrication process and reduces the cost. The Si@SiO2@CNF composite retains excellent performanceof 903.7 mAh g−1 beyond 100 cycles at 100 mA g−1, and a remarkable rate capacity of 634.6 mAh g−1 after 300 cycles. The proposed facile and scalable synthesis means that this novel, flexible, and binder-free Si/C anode should have practical applications in next-generation, flexible, binder-free Li-ion batteries.

Photo and thermal crosslinked poly(vinyl alcohol)-based nanofiber membrane for flexible gel polymer electrolyte

Novel dual crosslinked nanofibrous membranes (DCNMs) were fabricated by a combination of UV-photocrosslinking and thermal sol-gel crosslinking procedures and used as a matrix for gel polymer electrolytes for lithium-ion batteries (LIBs). Flexible nanofibrous membranes were obtained from the solution of poly(vinyl alcohol) (PVA), maleated PVA (PVA-MA), polyethylene glycol diacrylate (PEGDA), and tetraethyl orthosilicate (TEOS) by electrospinning technique. As a matrix for gel polymer electrolyte (GPE), it showed significantly higher ionic conductivity of 1.98 × 10−3 S cm−1 than the commercial separators and pure PVDF based GPE. Incorporation of TEOS into the membrane composition, and formation of siloxane bonds (Si–O–Si) greatly increased the conductivity providing excellent mechanical and thermal stability. The assembled lithium metal cell with LiFePO4 cathode exhibited excellent cycling performance and delivered a high reversible capacity of 133 mA h g−1 at 0.1 C and retained 87% of the initial discharge capacity after 150 cycles with a stable coulombic efficiency near 100%. The GPE could substantially suppressed the growth of Li dendrites during the stably cycles up to 1000 h, while the cell with the commercial separator failed within 800 h. In consequence, this novel DCNM possesses a potential for application in flexible and safe Li-ion and Li-metal batteries.

Co0.85Se nanosheet anchored on carbon fibers as anode materials for high-performance flexible Li-ion batteries

The rational design of the flexible anode with high reversible capacity and cycle stability for lithium-ion batteries (LIBs) has broad development prospects. A simple self-assembly method at room temperature for preparing N-doped Co0.85Se nanosheets anchored on carbon fibers as anode material for flexible Li-ion batteries is introduced in this work. The cost-effective compressed mask with abundant hydroxyl groups that can better anchor the MOFs (ZIF-67) is used as carbon source. The carbon fibers in composite Co0.85Se@Carbon Mask Fibers (Co0.85Se@CMF) provide a 3D conductive network to build continuous transmission channel for electron and ion, and also reduce the volume change-effect during charging&discharging process, which make the composite show a superior performance in LIBs. After 800 cycles, the average capacity attenuation of the composite is 0.065% per cycle, which shows the extremely possible application prospects of the composite in terms of capacity and cycle stability.

LiCrTiO4-MWCNT self-standing electrodes as high performance anode for flexible Li-ion batteries

Lithium chromium titanium oxide (LiCrTiO4, LCT) powder was synthesized using solid state reaction. Nanocomposites of LiCrTiO4 particles and Multi-walled carbon nanotubes (MWCNTs) as self-standing anodes were prepared using tape-casting method with and without binders. The structural and morphological studies were conducted using various techniques such as X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy. LCT self-standing electrode with polyvinyl alcohol delivered high initial discharge capacity of 158 mA h g−1 at 1C rate, comparable to the theoretical capacity (157 mA h g−1) of LiCrTiO4. Moreover, an outstanding cyclic performance with ~96% capacity retention was displayed at 1C (100 cycles) and 10C (500 cycles) rate. We believe that this nanocomposite is a good potential candidate for self-standing anode of high-energy flexible Lithium-ion battery.