Capacity Cycling Stability Research Articles

High‐Safety Lithium Metal Batteries Enabled by Additive of Fire‐Extinguishing Microcapsules

ABSTRACTLithium metal battery (LMB) is regarded as one of the most promising high‐energy energy storage systems. However, the high reactivity of lithium metal and the formation of lithium dendrites during battery operation have caused safety concerns. Herein, we present the design and synthesis of fire‐extinguishing microcapsules to enhance LMB safety. The encapsulation strategy addressed perfluoro(2‐methyl‐3‐pentanone)'s volatility and storage challenges, yielding microcapsules with stable and uniform size distributions. The rapid release and effective fire‐extinguishing performance of the microcapsules upon exposure to high temperatures has been demonstrated. Integration of these microcapsules into LMBs showed no significant impact on electrochemical performance, maintaining high lithium‐ion conductivity, and stable cycling capacity. Notably, practical safety tests on pouch cells indicated that the presence of microcapsules effectively prevented ignition and improved thermal stability under mechanical damage and flame intrusion, underscoring their potential for significantly improved battery safety. These findings provide a robust strategy for mitigating fire hazards of high‐energy‐density battery systems without compromising their electrochemical performances.

Strategically Modified Ligand Incorporating Mixed Phosphonate and Carboxylate Groups to Enhance Performance in All‐Iron Redox Flow Batteries

AbstractIron redox flow batteries (Fe‐RFBs) hold significant promise for achieving cost‐effectiveness and utilizing abundant materials for stationary energy storage applications. Here, a design of a novel Fe complex utilizing a nitrogenous phosphonate/carboxylate mixed ligand, N,N‐Bis(phosphonomethyl)glycine (BMPG), is presented to achieve high performance Fe anolyte. Compared to its all‐phosphonate form, nitrilotri(methylphosphonic acid) (NTMPA), the new complex Fe(BPMG)2 demonstrates a negatively shifted redox potential, resulting in ≈0.07 V (≈10%) increase in battery output voltage. Full battery testing paired with ferrocyanide catholyte demonstrates stable cycling (capacity degradation <0.0001%/cycle) over 730 consecutive charge/discharge cycles with Coulombic Efficiency of 100% at a current density of 20 mA cm−2 under near neutral pH (≈8). Of particular interest, density functional theory (DFT) studies and operando Raman measurements provide strong evidence supporting a molecular structure in BPMG, which reveals the mixed phosphonate/carboxylate groups in BPMG maintain the octahedral coordination of the Fe ion center with phosphonates exclusively, while leaving the carboxylate unbound for both Fe(II) and Fe(III) complexes. This structural similarity between BPMG‐based Fe(II) and Fe(III) complexes effectively mitigates the slow redox reaction kinetics observed in Fe(NTMPA)2 anolyte, where significant ligand reorientation occurs between Fe(II) and Fe(III) complexes.

Boosting proton intercalation via sulfur anion doping in V2O3 cathode materials towards high capacity and rate performance of aqueous zinc ion batteries

Aqueous zinc-ion batteries (ZIBs) are a prospective solution for grid-scale energy storage. V2O3 has emerged as a promising cathode candidate with reversible two-electron redox capability for ZIBs. However, it still faces problems such as poor electronic conductivity and sluggish ion embedding kinetics. Herein, we report sulfur anion-doped V2O3 with tunneled structure based on a facile carbothermal reduction method, which can exhibit the significant impact of sulfur anion-doping on proton storage in vanadium-based cathode materials for high capacity and rate performance of ZIBs. The covalent bonds in S-V-O lead to accelerated charge transfer and elevated electronic conductivity. In-situ X-ray diffraction, synchrotron-based X-ray absorption spectroscopy combined with DFT calculations demonstrate that S doping effectively diminishes the adsorption and embedding energies of H+ in V2O3 and greatly boosts proton insertion kinetics. The co-intercalation of H+/Zn2+ helps compensate for the deficiency of Zn2+ insertion/extraction kinetics. Amorphous transition of crystalline V2O3 initiated from initial charging is conducive to mitigating stress and retaining stable cycling capacity. The typical sulfur-doped V2O3 achieves remarkable capacity (470.4 mAh·g−1 at 0.5 A·g−1), excellent rate capability (264.6 mAh·g−1 at 10 A·g−1) and stable long-term cyclability (231.2 mAh·g−1 at 10 A·g−1 after 2000 cycles). Furthermore, the corresponding pouch cells can deliver 26 mAh at 1 A·g−1 after 250 cycles, holding great potential for practical applications.

Vitrified Metal-Organic Framework Composite Electrolyte Enabling Dendrite-Free and Long-Lifespan Solid-State Lithium Metal Batteries.

Solid-state lithium metal batteries (LMBs) are still plagued with low ionic conductivity and inferior interfacial contact, which hinder their practical implementation. Herein, a quasi-solid-state composite electrolyte, poly(1,3-dioxolane) (PDOL)/glassy ZIF-62 (PGZ) with fast ion transport and intimate interface contact, is fabricated via in situ polymerization. The in situ polymerization of DOL in an electrolyte matrix not only improves the exterior interface between electrolyte/electrode but also optimizes the inner interfaces among glassy particles, rendering PGZ as an uninterrupted ionic conductor. Moreover, PGZ inherits the superior ionic conductivity and the robust dendrite prohibition of glassy MOFs originating from their grain-boundary-free nature, isotropy, and abundant groups containing N species. As expected, our proposed PGZ exhibits a prominent ionic conductivity of 6.3 × 10-4 S cm-1 at 20 °C. Li|PGZ|LiFePO4 delivers an outstanding rate performance (103 mAh g-1 at 4C) and a stable cycling capacity (118 mAh g-1 at 1C over 1000 cycles). PGZ also presents excellent low-temperature cycling performance with 75 mAh g-1 for 480 cycles at -20 °C and excellent flame retardance. Even at a high loading of 12.1 mg cm-2, it can still discharge at 140 mAh g-1 for 100 cycles. Hence, PGZ prepared via in situ polymerization holds enormous prospects as a solid-state electrolyte for high-performance and safe LMBs.

Electrochemical Activation of Ordered Mesoporous Solid Electrolyte Interphases to Enable Ultra‐Stable Lithium Metal Batteries

AbstractIn Li metal batteries, the rational construction of artificial solid electrolyte interphase (ASEI) can homogenize the Li‐ion flowing and Li‐mass plating/stripping, and reinforce the mechanical and electrochemical stabilities of electrode–electrolyte interface. Here, an ordered‐mesoporous powder zirconium oxophosphate (ZrOP) is proposed to construct a Li‐ion conductive ASEI by brushing ZrOP on metallic Li. The P‐induced amorphization in ZrOP is expected to accelerate the spontaneous lithiation reaction and promote the generation of P‐contained Li‐ion conductors and LiF domains in ASEI during Li anode cycling. The electrochemical activation of ASEI with promoted ionic conductivity and interconnected porous network is favorable for the homogeneous nucleation and growth of Li metal grains (with ≈10 µm in size), and the suppression of Li dendrites and volume expansion during long‐term Li plating and stripping. The ZrOP‐modified Li symmetric cell enables a long lifespan of over 1600 h at 1 mA cm−2, and the corresponding LiNi0.8Co0.1Mn0.1O2 (NCM811) based full cell displays a stable cycling for at least 300 cycles with a capacity retention of 80% at 1 C. The modified thin Li foil (40 µm in thickness) anode also enables a multilayered pouch cell based on a high‐loading NCM811 cathode with stable cycling and reversible capacity over 1 Ah.

Development of Lithium/Sodium-Ion Battery Electrodes Based on Solvent Engineered Tin(II) Oxide Nanomaterials

With the global economy pushing towards a greener and cleaner energy future for the world, renewable energy storage technologies must continue to develop and improve to allow for a seamless transition from the ways of the past to a carbon neutral future. To this end, renewable battery technology and in particular the capacity of the anode must be improved. Furthermore this improvement must be made across various battery technologies (Lithium/Sodium-ion) and be cost-effective to allow for its widespread implementation and use worldwide.In this work, Tin(II) Oxide (SnO)/single wall carbon nanotube (SWCNT) composite electrodes are analysed as a possible alternative dual anode material for both lithium (LIB) and sodium-ion batteries (NIB). The LIB is limited by the current commercial anode material of graphite with a relatively low theoretical capacity of 372 mAh g-1 whilst NIBs use hard carbon with a capacity of roughly 300 mAh g-1. Alloy/de-alloy materials are envisioned to be a suitable candidate for next generation LIBs/NIBs due to their large specific capacities (875mAh g-1/ 847 mAh g-1 for SnO respectively) although major drawbacks concern the poor cycling life associated with the volume change and the associated irreversible capacity. To overcome such issues the downsizing of materials and the fabrication of composites which incorporate both lithium active and inactive material are viewed as promising solutions. Nanostructured metal oxides, forming an inactive oxide matrix are appealing candidates.Through the implementation of a solvent engineered wet chemistry synthesis, various layered SnO microparticles are produced with several morphologies well-suited to energy storage applications. This synthesis method is facile, scalable and is favourable in comparison to hydrothermal synthesese normally used to synthesise nanomaterials. While SWCNTs are themselves not suited towards energy storage applications, their incorporation in the electrodes allows them to act as a conductive additive at a lower weight loading than other conventional carbon sources (carbon black/graphite), presenting a more effective strategy to form an effective electrical percolation network while also removing the need for polymer binders/copper current collector.The optimised morphology of SnO produces a high capacity, high rate and stable anode for LIB technology. An initial coloumbic efficiency (ICE) in excess of 80% is recorded and a stable cycling capacity of 815 mAh g-1 at 0.5C after 300 cycles is also achieved, demonstrating its long term stability. A maximum capacity of 980 mAh g-1 is recorded at 0.1C, whilst high rate capacities of 775, 671 and 364 mAh g-1 are recorded at 1,2 and 5C respectively. Furthermore a full-cell is composed with a NMC cathode to demonstrate a potential full-cell real world device. As an NIB anode, a maximum capacity of 568 mAh g-1 was recorded at 0.05C, whilst a low ICE of 50% proves an issue under further investigation. Furthermore a cycling capacity of 595 mAh g-1 is recorded after 50 cycles at 0.1C, dropping to 360 mAh g-1 at 100 cycles which is still in excess of that recorded for hard carbon in NIBs.A high capacity, scalable and cost effective anode has been developed that is interchangeable between LIBs/NIBs and exceeds the performance of the current commercial anodes. Reference s : [1] S. Jaśkaniec, S. R. Kavanagh, S. Ryan, J. Coelho, C. Hobbs, A. Walsh, D. O. Scanlon and V. Nicolosi, npj 2D Mater. Appl., 2021, 5, 27. [2] J. H. Shin and J. Y. Song, Nano Converg., 2016, 3(1), 9. [3] F. Zhang, J. Zhu, D. Zhang, U. Schwingenschlögl and H. N. Alshareef, Nano Lett., 2017, 17, 1302–1311.

Revealing the enhancement mechanism of carbon-encapsulated surface-strained MoNi4 bimetallic nanoalloys toward high-stability polysulfide conversion with a wide temperature range

Bimetallic alloy catalysts, due to their more adsorption sites, more abundant electronic structures, and higher catalytic properties than single-metal ones, have attracted much interest in the field of lithium–sulfur batteries (LSBs). However, many LSBs with bimetallic alloys often suffered from their low cycling stability, which was caused by the over-strong adsorption and the bad chemical stability of the catalysts. Herein, in-situ carbon-encapsulation-induced strain relaxation strategy has been adopted to balance the adsorption and catalytic properties of the MoNi4 bimetallic nanoalloy catalyst for LSBs. As a result, the cathode with strained-MoNi4 embedded carbon nanofibers (CNF@s-MoNi4) delivers a high capacity (1632.5 mAh g−1 at 0.1 C), a superior rate capability (retaining 832.4 mAh g–1 at 5.0 C) and excellent cycling stability (decaying rate of 0.0204% per cycle over 520 cycles at 1.0 C). Even at high rates, the CNF@s-MoNi4 can keep a stable cycling capacity (827.5 mAh g–1 and 447.7 mAh g–1 after 250 cycles at 5.0 C and 10.0 C, respectively). Besides, the CNF@s-MoNi4 LSB also exhibits an excellent wide-temperature-range adaptability (-30 ∼ 50°C) and a superior dynamic bending stability. This study would provide a feasible method for developing high-capacity and long-life LSBs with a wide temperature range demand.

Synergistic effect on the improved lithium ion storage performance in the porous Fe2O3@Fe3C@C composite

The porous Fe2O3@Fe3C@C composite was synthesized by a simple two-step thermal treatment and its structure, morphology, lithium ion storage performance and diffusion kinetics were discussed. Benefitting from the high theoretical capacity of Fe2O3 and fast kinetics of Fe3C, the Fe2O3@Fe3C@C composite exhibits a stable cycling capacity of 800.3 mAh g−1 after 100 cycles at 0.1 A g−1 with superior rate capability. The CV and in-situ EIS analysis results reveal that the Fe2O3@Fe3C@C composite has reversible redox reaction, stable solid electrolyte interphase films and low charge transfer resistance during the discharging and charging process. In addition, the lithium ion diffusion coefficients of the Fe2O3@Fe3C@C composite at different voltage states are investigated by GITT measurement. This work can provide an effective strategy for synthesis of metal oxide@metal carbide composite for lithium-ion batteries.

Cobalt, nitrogen co-doped microporous carbon matrix derived from metal organic frameworks toward high specific capacity room temperature sodium sulfur batteries

Room-temperature sodium-sulfur (RT Na–S) batteries have been getting increasing attention in the field of energy storage system thanks to their advantages of high specific capacity, good safety, low cost and environmental friendliness. However, limited by the low conductivity, large volume change and complex reaction, the utilization rate of active sulfur is still unacceptable, which delays the practical application of RT Na–S battery. Herein, derived from CoZn-ZIFs, a cobalt, nitrogen co-doped microporous carbon matrix (Co,N-MPC) has been devised to exploit capacity of active sulfur as fully as possible. In the case of appropriate Co content, the affluent micropores limit the size of sulfur and inhibit the volume change. And the well-dispersed Co and N elements improve the adsorption of the matrix to sulfur species and promote their transformation process. Owing to their synergistic effect, the S@Co,N-MPC-10% electrode presents stable cycling (1134.63 mAh g−1 after 100 cycles at 0.2 C) and high rate capacity (835.01 mAh g−1 at 3.0 C). This work might provide beneficial insights to the development of efficient sulfur matrixes of RT Na–S batteries.

High Loading Sulfur Cathodes by Reactive‐Type Polymer Tubes for High‐Performance Lithium‐Sulfur Batteries

AbstractSimultaneously attaining high gravimetric energy density (Eg) and volumetric energy density (Ev) in lithium‐sulfur (Li–S) batteries is a longstanding challenge that has to be solved for practical application, which demands breakthroughs in electrode materials with optimized functionality and structure. Herein, anthraquinone‐containing, reactive‐type polymer tubes (PQT) that can be used to regulate the redox chemistry of sulfur species are designed and prepared for practical Li–S batteries. PQT favors a similar redox potential window as sulfur, which effectively facilitates the immobilization and conversion of sulfur species through a reversible lithiation/delithiation process. Its tubular structure and high tap density is vital to the fabrication of intact electrode with high sulfur loading and minimizing electrolyte intake during battery operation. With all these contributions, Li–S battery with PQT/S cathode exhibits a stable cycling capacity (73% at 2.0 C over 1000 cycles), remarkable rate performance (514.2 mAh g−1 at 10 C), and a high areal capacity of 7.20 mAh g−1 with high sulfur loading under lean electrolyte condition. More importantly, the assembled Li–S pouch cell delivers an Eg of 329 Wh kg−1 and an Ev of 401 Wh L−1, which meets the requirement for practical operation.

Functionally Gradient Silicon/Graphite Composite Electrodes Enabling Stable Cycling and High Capacity for Lithium-Ion Batteries

Silicon (Si) is regarded as one of the most promising anode materials for high-energy-density lithium (Li)-ion batteries (LIBs). However, Li insertion/extraction induced large volume change, which can lead to the fracture of the Si material itself and the delamination/pulverization of electrodes, is the major challenge for the practical application of Si-based anodes. Herein, a facile and scalable multilayer coating approach was proposed for the large-scale fabrication of functionally gradient Si/graphite (Si/Gr) composite electrodes to simultaneously mitigate the volume change-caused structural degradation and realize high capacity by regulating the spatial distributions of Si and Gr particles in the electrodes. Both our experimental characterizations and chemomechanical simulations indicated that, with a parabolic gradient (PG) distribution of Si through the thickness direction that the two Si-poor surface layers guarantee the major mechanical support and the middle Si-rich layer ensures the high capacity, the as-prepared PG-Si/Gr electrode can not only effectively improve the stability of the electrode structure but also efficiently enable high capacity and stable electrochemical reactions. Consequently, the PG-Si/Gr electrode with a mass loading of 3.15 mg cm-2 exhibited a reversible capacity of 579.2 mAh g-1 (1.82 mAh cm-2) after 200 cycles at 0.2C. Even with a mass loading of 8.45 mg cm-2, the PG-Si/Gr anodes still delivered a high reversible capacity of 4.04 mAh cm-2 after 100 cycles and maintained excellent cycling stability. Moreover, when paired with a commercial LiNi0.5Mn0.3Co0.2O2 (NCM532) cathode (9.56 mg cm-2), the PG-Si/Gr||NCM532 full cell revealed an initial reversible areal capacity of 1.64 mAh cm-2 and sustained a stable areal capacity of 0.94 mAh cm-2 at 0.2C after 100 cycles.

Boosting the Rate Performance and Capacity of Sb2S3 Nanorods Cathode by Carbon Coating in All‐Solid‐State Lithium Batteries

AbstractAntimony sulfide (Sb2S3) is a promising electrode material. However, its poor electronic/ionic conductivity severely hinders its practical application. Herein, carbon‐coated Sb2S3 nanorods (Sb2S3@C) are synthesized to address this issue. The electrochemical performance of the Sb2S3@C is evaluated in all‐solid‐state lithium batteries (ASSLBs) using InLi anode and Li10Si0.3PS6.7Cl1.8 solid‐state electrolytes. The Sb2S3@C cathode delivers the 1st cycle discharge capacity of 711 mAh g‐1 and a stable cycling capacity of 431 mAh g‐1, which are much higher than the 1st cycle discharge capacity of 125 mAh g‐1 and a stable cycling capacity of 320 mAh g‐1 for the uncoated Sb2S3 cathode. In situ transmission electron microscopy reveals that the carbon coating layer acts as an electronic/ionic conductive conduit, which boosts the charge transfer in the electrode dramatically. Consequently, the Sb2S3@C electrochemistry quickly evolves from intercalation to conversion to full alloying. However, the Sb2S3 nanorods without carbon coating undergo sluggish intercalation and conversion reactions, and the alloying reaction is almost impeded, severely limiting the capacity. Therefore, the Sb2S3@C electrode is fully utilized thus delivering much higher capacity and rate performance than the non‐coated Sb2S3 electrode. These results demonstrate that Sb2S3@C is a promising high‐energy‐density cathode for ASSLBs.

Interfacial Engineering with a Nanoparticle-Decorated Porous Carbon Structure on β″-Alumina Solid-State Electrolytes for Molten Sodium Batteries.

We present a novel anode interface modification on the β″-alumina solid-state electrolyte that improves the wetting behavior of molten sodium in battery applications. Heat treating a simple slurry, composed only of water, acetone, carbon black, and lead acetate, formed a porous carbon network decorated with PbOx (0 ≤ x ≤ 2) nanoparticles between 10 and 50 nm. Extensive performance analysis, through impedance spectroscopy and symmetric cycling, shows a stable, low-resistance interface for close to 6000 cycles. Furthermore, an intermediate temperature Na-S cell with a modified β″-alumina solid-state electrolyte could achieve an average stable cycling capacity as high as 509 mA h/g. This modification drastically decreases the amount of Pb content to approximately 3% in the anode interface (6 wt % or 0.4 mol %) and could further eliminate the need for toxic Pb altogether by replacing it with environmentally benign Sn. Overall, in situ reduction of oxide nanoparticles created a high-performance anode interface, further enabling large-scale applications of liquid metal anodes with solid-state electrolytes.

Facile synthesis of black phosphorene via a low melting media assisted ball milling

Few-layer phosphorene (FLP) has attracted strong research interest due to its extraordinary physical and chemical properties. However, an efficient and rapid fabrication of high-quality FLP is still unavailable. Herein, a simple and efficient low melting media-assisted ball milling (LMMBM) approach is developed to prepare FLP in large quantities. The phase change of the LMM at higher temperatures leads to FLP with larger lateral dimensions compared to the ones obtained via dry solid state ball milling. Transmission electron microscope (TEM) studies indicated that liquid facilitates the slipping/curling of black phosphorus (BP) layers under the shearing force generated during ball milling. When used as an anode in Lithium-ion batteries, the FLP-C composite exhibits high initial Coulombic efficiency, stable cycling and rate capacity. This LMMBM approach can be adopted for mass production of other two-dimensional materials from their bulk counterparts.

Turning rice husks to a valuable boron and nitrogen co-doped porous C/SiOx composite for high performance lithium-ion battery anodes

For the exploitation of green biomass waste, boron (B) and nitrogen (N) co-doped porous C/SiOx composites ([email protected]/SiOx) have been successfully synthesized applying rice husks (RHs) as both C and Si sources and NH4HB4O7 as the porogen reagent and heteroatom source via a one-step calcination route. The volume fluctuation of SiOx can be effectively relieved and the electronic conductivity can be substantially enhanced with the homogeneous distribution of SiOx particles in the B, N co-doped porous C matrix. Specially, B, N co-doping effectively reduces the transmission barrier of Li+ in C skeleton of C/SiOx. The unique porous architecture, large specific surface area and B, N co-doping endow [email protected]/SiOx with the large reversible capacity, exceptional rate property and superior cycling stability. As lithium-ion batteries (LIBs) anodes, the optimized [email protected]/SiOx exhibits the cycling capacity of 1165 mAh/g at 100 mA/g and ameliorated initial coulombic efficiency (CE) of 74.3%. Even at 1.0 A/g, a stable cycling capacity of 650 mAh/g still can be obtained after 1200 cycles. This research offers a potential, relatively effective, cheap and environmental design of heteroatom doped biomass materials with enhanced Li+ storage performance.

Anion-Doped Cobalt Selenide with Porous Architecture for High-Rate and Flexible Lithium-Sulfur Batteries.

Emerging catalytic host for sulfur is an effective approach to breaking the limits of lithium-sulfur batteries for practical applications. Herein, the hydrangea-shaped Co0.85 Se electrocatalyst with macroporous architecture is synthesized. Besides, to improve the electronic conductivity of Co0.85 Se, some defects (S-doped) are introduced into the structure of crystals. The S-doped Co0.85 Se exhibited an outstanding electrocatalytic effect on lithium polysulfides conversion and can induce and regulate uniform growth of insoluble Li2 S on its surface due to the synergistic adsorption by Se and S. As a result, the S/C cathode achieved a high initial capacity of 1340.6 mAh g-1 at 0.5 C and a stable cycling capacity of 666.6 mAh g-1 at 1 C after 500 cycles by 5wt% Co0.85 SeS additions. Moreover, high S loading cathodes are designed through in situ synthesis of Co0.85 SeS on flexible carbon cloth (Co0.85 SeS@CC). The porous and open framework of Co0.85 SeS@CC facilitated electrolyte infiltration and accommodated the volume change of sulfur during the charge/discharge process. Taking by these advantages, a high areal capacity of 9.663 mAh cm-2 is achieved at a high sulfur loading of 9.98mg cm-2 . Even at a high current density of 15mA cm-2 , a reversible capacity of 603.7 mAh g-1 is maintained at a sulfur loading of 6.52mg cm-2 . This proposed work provides a feasible approach to high-rate and flexible Li-S batteries.

Tin nanoparticle/3D framework carbon composite derived from sodium citrate as the stable anode of lithium-ion batteries

Sn-based anode materials have gained more attention for application in lithium-ion batteries (LIBs), due to tin having the characteristics of high specific capacity, low cost, and environmentally friendly. However, low capacity retention due to the large volume changes upon lithiation/delithiation limits their further development. In this paper, tin nanoparticle/3D framework carbon composite (denoted as Sn@SC) is obtained by calcining the composite of trisodium citrate and stannous sulfide. The Sn@SC composite delivers a stable cycling capacity of 410.9 mAh/g after 150 cycles and 300.1 mAh/g after 950 cycles at 1 A/g. The excellent electrochemical performance can be assigned to the fact that the hollow porous carbon can provide enough space for the volume change of tin nanoparticles in the step-by-step alloying process and shorten the electron transport path, thus increasing the structural stability and rate capability.

Lithium Polymer Battery with PVDF-based Electrolyte Doped with Copper Oxide Nanoparticles: Manufacturing Technology and Properties

An overview of electrolyte materials for lithium polymer batteries and the prospects for adding metal oxide nanoparticles to the electrolyte are presented in this paper. A procedure for the synthesis of a gel polymer electrolyte based on polyvinylidene fluoride doped with copper oxide nanoparticles is also described, and the ionic conductivity is measured by the electrochemical impedance spectroscopy. Cells with the synthesized electrolyte and LiFePO4 electrode have been assembled and cycled at different currents. Stable cycling and high capacity have been exhibited by the cell with electrolyte doped with copper oxide nanoparticle (wt. 0.1%).

Surface trace doping of Na enhancing structure stability and adsorption properties of Li1.6Mn1.6O4 for Li+ recovery

Li1.6Mn1.6O4 (LMO) is a dominant adsorbent for lithium recovery from solutions resulted from its high theoretical adsorption uptake and a low loss rate of Mn, which can potentially be further improved by trace doping. We achieve stable cycling and high adsorption capacity of Li1.6Mn1.6O4 from aqueous lithium resources by Na doped (LMO-Na). The Mn dissolution is decreased from 5.4% (bare adsorbent) to 4.4%, and the uptake is increased from 33.5 mg/g to 33.9 mg/g (CLi+: 24 mmol/L). Furthermore, DFT calculations predict that Na replace for Li at 16d sites, result in an enhancement of the Li+ adsorption rate and structure stability of LMO. The loss rate of Mn in cycling process is restrained by Na doped, which may result from reducing the content of low valent Mn3+ and improving the structural stability of material. The effect of Na substitution on adsorption capacity and structure stability is discussed.

Composite of nanocrystalline cellulose with tin dioxide as Lightweight Substrates for high-performance Lithium-ion battery

Nanocrystalline Cellulose (CNC) has smoother surfaces, better optical transparency and higher mechanical strength in comparison with various cellulose fibers. These properties combined with their low cost, light weight, and flexiblility indicate CNC’s great potential as an attractive candidate for preparation of carbon materials, which can be promising electrode for Lithium-ion batteries. However, CNC cannot be directly used in battery fabrication because of its electrically non-conductive property. Wherefore, using pyrolysis to convert CNC into conductive materials is extensively investigated. In our study, high temperature range is used to convert nanocrystalline cellulose into highly conductive carbon material and used in Lithium-ion batteries. The nanocellulose powder after pyrolysis from 800 °C and 1,600 °C is used as active material in Lithium-ion battery electrodes, and the results obtained show a good electrochemical performance with stable cycling capacity. Following, the carbon network obtained through the pyrolysis (800 °C and 1,600 °C) of nanocrystalline cellulose incorporation with tin dioxide (SnO2) was also used as electrode material in Lithium-ion batteries, resulting in stability, outstanding capacity and better performance in comparison with other carbon-based materials.