Electrochemical Performance For Lithium-ion Batteries Research Articles

Preparation of NiMn2O4-NiMnO3@MoS2 Nano-composites with Enhanced Electrochemical Performances for Lithium-ion Batteries

Preparation of NiMn2O4-NiMnO3@MoS2 Nano-composites with Enhanced Electrochemical Performances for Lithium-ion Batteries

Research Progress on the Application of Nanomaterials in Lithium-Ion Battery Cathode Materials

Energy scarcity and environmental pollution are getting worse as science and technology advance, which has a significant influence on people's living conditions. Therefore, in light of the present sustainable development plan, the discovery and implementation of new energy sources are crucial for sustainable development. Lithium-ion batteries have been playing an increasingly significant role in the field of smart grids, electric vehicles, and personal electronic devices due to the fact that solar, wind, hydropower, and nuclear energy are new renewable energy sources in this context, but these energy sources are seasonal, regional, and discontinuous. There are currently more demanding specifications for lithium-ion batteries, including high energy density and high power density, due to the growth of electric vehicles and other energy storage technologies. In order to enhance the electrochemical performance of lithium-ion batteries, this thesis focuses on the incorporation of nanomaterials into the cathode materials. It is discovered that there is still much opportunity for nanomaterial development in the cathode materials of batteries.

Experimentaland computational analysis of metal oxide nanomaterials for lithium-ion batteries

Lighter, more effective, and powered by sustainable energy sources are the goals of electric vehicles. In addition to helping to achieve many of these goals for improved vehicle convenience, performance, and safety, nanotechnology is crucial for reducing size, weight, and power consumption, all of which are crucial for long-range coverage. Nanoscale electrodes have low impedance growth, which prevents significant power loss while cycling. They also have a larger electrode/electrolyte contact surface, which boosts the charge/discharge rate to provide the most power. The new nanostructured cathode materials and their impact on the electrochemical performance of lithium-ion batteries are discussed in this research. The creation of high energy density Cathode materials at the nanoscale enhances battery performance. This article explains how to make lithium manganese spinel and its derivatives, such as transition metal oxide (LiNi0.5Mn1.5O4), using the co-precipitation process. LiNi0.5Mn1.5O4′s structural characteristics, as determined by X-ray diffraction (XRD), showed that the prepared sample primarily belongs to cubic crystal form with Fd3m space group, with lattice parameter a = 8.265 A° and an average crystal size of 31.59 nm. The experimental results were compared to computation details from first-principles calculations performed using Material Studio version 6.0 and Atomistic Tool Kit, Quantum wise softwares. Methods of first-principles computation play a significant role in the development and improvement of electrode materials. In this paper, we provide a summary of the computational strategy used to create LiNi0.5Mn1.5O4 as the cathode material for lithium-ion batteries.

Pressure-induced phase transition toward high symmetry in zero-strain Li2TiO3.

As a typical layered oxide material, Li2TiO3 has attracted considerable attention in the energy revolution and military industries, owing to its lithium-rich and "zero-strain" characteristics. However, its phase-transition behavior under high pressure remains unclear. Herein, we report a second-order phase transition from the monoclinic phase to a higher-symmetry phase in nano-polycrystalline Li2TiO3 at 43 GPa by in situ high-pressure Raman experiments and first-principles calculations at 300 K. As validated by the experiments and calculations, the distortion of layered oxide-TiO6 in Li2TiO3 is crucial in the phase transition. By modulating the gap between octahedral-TiO6 layers, we propose a potential Li2TiO3 structural model for improving the electrochemical performance of lithium-ion batteries. Our findings suggest that, based on its high-pressure phase, Li2TiO3 is a promising candidate for layered cathode materials and solid tritium breeding materials for lithium-ion batteries.

Crystalline-amorphous core-shell copper vanadate coralline as anode material for high-performance lithium-ion battery

Constructing electrode materials with core-shell structures is considered an effective strategy to enhance the electrochemical performance of lithium-ion batteries (LIBs) anode. Herein, a novel amorphous copper vanadium oxide coated crystalline copper vanadates was designed and synthesized through a template transformation route. The copper vanadates showed a three-dimension coralline morphology assembled by nanoparticles. When applied to the LIBs anode, the as-prepared electrode exhibited a large reversible capacity (967 mAh g−1), superior rate performance (390 mAh g−1 at 5 A g−1), and cycle stability (98.2% retention after 200 cycles). This enhanced lithium storage was related to the synergistic effect of the amorphous buffer layer and abundant oxygen vacancies that could buffer volume expansion and promote the pseudo-capacitance behavior.

Synergistic Engineering of Defects and Architecture in a Co@Co3O4@N-CNT Nanocage toward Li-Ion Batteries and HER.

The design and synthesis of hollow and porous nanostructured electrode materials is an effective strategy to improve the electrochemical performance of lithium-ion batteries and the hydrogen evolution reaction (HER). Herein, we synthesize hollow and porous Co@Co3O4 nanoparticles embedded in N-doped CNTs (N-CNTs) with rich surface defects through a two-step calcination strategy. The formation mechanism is explored. The influence of oxygen vacancies regulated by the nanoscale Kirkendall effect on the electrochemical performance of the electrode is elucidated. The Co@Co3O4@N-CNTs exhibit remarkable activity for catalyzing the HER with a low onset overpotential of 296 mV (a low Tafel slope of 116.2 mV dec-1), much better than Co3O4@N-CNTs (315 mV for overpotential and 124.2 mV dec-1 for Tafel slope). Significantly, the Co@Co3O4@N-CNTs deliver a high discharge capacity of 990 mA h g-1 after 600 cycles at 0.1 A g-1. Our nanostructure strategy can provide new insights into the strategy for high-rate and highly stable energy storage systems.

Microstructure and surface engineering through indium modification on Ni-rich layered cathode materials for enhanced electrochemical performance of lithium-ion batteries

Ni-rich layered lithium transition metal oxides have been considered as one of the most promising cathodes for next-generation lithium-ion batteries (LIBs) because of their high capacities and affordable costs. However, they still suffer bulk and surface structural instability, leading to rapid performance decay and subsequent cathode failure. In this context, Ni-rich layered cathodes with indium modified crystal and surface structures are developed by a simple one-pot calcination approach. Battery tests manifest that the indium modified LiNi0.8Co0.1Mn0.1O2 electrodes exhibit remarkably enhanced rate capability and cycling stability compared to the pristine one, including under high operating voltage condition. Further studies evidence a simultaneous mitigation of intra/inter-granular mechanical cracks and resistive surface films growth, which directly embodied in a dramatically suppressed ohmic loss after long-term cycling. The improved microstructural and surface stability are attributed by the synergistic functions of indium modification. On the one hand, trace amount of In3+ occupy crystalline Li+-site, which not only dissipate the intrinsic lattice strain during cycling, but also reduce Li+/Ni2+ antisite to avoid the undesired layer to rock-salt phase transformation. On the other hand, the rest of indium deplete lithium residues, and form conductive LiInO2 adherent coatings to protect the cathode from side reactions with electrolyte. The present work demonstrates that microstructure and surface engineering through indium modification offers a promising design strategy for further improvements of Ni-rich layered cathodes.

Layered Silicon/Titanium Composite and Its Electrochemical Performance for Lithium-Ion Batteries

Layered Silicon/Titanium Composite and Its Electrochemical Performance for Lithium-Ion Batteries

Li4Ti5O12 Coated by Biomass-Derived Carbon Quantum Dots as Anode Material with Enhanced Electrochemical Performance for Lithium-Ion Batteries

Li4Ti5O12 (LTO) is a promising anode material for lithium-ion batteries (LIBs) due to its stable reversibility, high-rate cyclability, and high operational potential. On the other hand, it suffers from poor electronic conductivity and low capacitance. To overcome these disadvantages, modification of the LTO surface is frequently undertaken. Considering this idea, the production of a biomass-derived carbon-coated LTO material (LTO/C) and its application as an anode in LIBs is described in this work. The carbon precursor was obtained from commercial carrot juice, which was degraded using microwaves. According to the UV studies, the carbon precursor revealed similar properties to carbon quantum dots. Then, it was deposited on LTO synthetized through a sol-gel method. The LTO/C electrode exhibited a high specific capacity of 211 mAhg−1 at 0.1 C. Capacity retention equal to 53% of the initial value was found for the charge–discharge rate increase from 0.1 C to 20 C. The excellent electrochemical performance of LTO/C was caused by the carbon coating, which provided (i) short diffusion pathways for the Li+ ions into the LTO structure and (ii) enhanced electronic conductivity. The obtained results indicated that biomass-derived carbon quantum dot-coated LTO can be considered as a promising anode for LIBs.

Cellulose microspheres enhanced polyvinyl alcohol separator for high-performance lithium-ion batteries

Separators typically play an important role in enhancing the electrochemical performance of lithium-ion batteries (LIBs), while the preparation of separators suffers good electrochemical performance and high stability. In this study, regenerated porous cellulose microspheres (RCM) were innovatively fabricated and the biodegradable RCM/Polyvinyl alcohol (PVA) separators were successfully prepared through simple mixing and solvent substitution. Interestingly, the RCM with rich carboxylic groups, not only function as nanofillers that increases the strength properties of the three-dimensional porous network, but also enhances Li+ transfer (due to the COO− and Li+ interactions), resulting in outstanding Li+ transference number (0.54) of the RCM/PVA separator. In addition, the RCM/PVA separator shows excellent thermal stability and high liquid absorption rate (481.25 %). The LiFePO4/3 % RCM-HCl/PVA/Li cell displayed a high discharge capacity of 152.6 mAh·g−1 after 200 cycles at 1C. This work provides a new light on the fabrication of biodegradable separators for LIBs via a novel and cost-effective strategy.

Improved Electrochemical Performance of NTs-WS2@C Nanocomposites for Lithium-Ion and Sodium-Ion Batteries.

Even though WS2 nanotubes (NTs-WS2) have great potential as anode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) thanks to their unusual layered structure, their conductivity and cycling stability are far from satisfactory. To tackle these issues, carbon-coated WS2 (NTs-WS2@C) nanocomposites were prepared through a facile synthesis method that involved precipitating a carbon precursor (20% sucrose) on WS2 nanotubes, followed by annealing treatment under an argon environment. Thanks to the presence of highly conductive and mechanically robust carbon on the outer surface, NTs-WS2@C nanocomposites show improved electrochemical performance compared with bare NTs-WS2. After 60 cycles at 80 mA g-1 current density, the cells display high capacities of 305 mAh g-1 in LIBs and 152 mAh g-1 in SIBs, respectively. As the current density increases to 600 mA g-1, it provides specific capacities of 209 and 115 mAh g-1, correspondingly. The enhanced electrochemical performance in LIBs and SIBs is primarily attributed to the synergistic effects of the tubular architecture of WS2, carbon network and stable nanocomposite structure, which can effectively constrain volume variation during the metal ions intercalation/deintercalation processes.

Multi-scale analysis of cathode microstructural effects on electrochemical and stress responses of lithium-ion batteries

The electrochemical and stress responses of lithium-ion batteries (LIBs) are highly dependent on the three-dimensional (3D) microstructure of electrodes, and substantial fundamental research is required to optimize the electrode design for high-energy, high-power LIBs with fast charging capabilities. Herein, we report a multi-scale LIB model that enables the examination of full-cell battery performance while investigating the detailed electrochemical and stress responses of the cathode using the variational multi-scale enrichment method. With the high computational efficiency of the developed model, the cathode microstructural effects were studied systematically by varying the particle size, volume fraction, and particle arrangement of 3D cathode microstructures at different C-rates. The results show that the arrangement of active material particles and their interconnectivity, rather than the particle size itself, are the determining factors for the spatial lithium-ion concentration and stress distribution of the cathode, affecting the overall electrochemical performance of LIBs. Our study provides valuable insights into the design and optimization of the cathode architecture to maximize the electrochemical performance under different operating conditions.

Flexible and heat-resistant polyphenylene sulfide ultrafine fiber hybrid separators for high-safety lithium-ion batteries

Separators play a critical role in the safety and electrochemical performance of lithium-ion batteries (LIBs). However, the commercial polyolefin-based separators encounter poor thermal stability and flame retardance, which have aroused severe safety issues. Herein, a flexible and heat-resistant porous separator based on sea-island polyphenylene sulfide (PPS) ultrathin fiber and glass nanofiber (GNF) network is rationally designed and successfully fabricated. This hierarchical network is bound via hot pressing and modification of silane coupling agent (γ-3-glycidoxypropyltrimethoxy silane, γ-GPS), endowing the separator with high flexibility and excellent mechanical performance. Also, this novel composite separator features distinguished thermal stability (without any heat shrink at 250 °C for 30 min) and flame retardant properties, guaranteeing the safety of the battery. Due to the inherent polarity and porous structure, the as-prepared PPS-mGNFs separator achieves a small contact angle (18.2°) of liquid electrolyte (LiPF6) and a high electrolyte uptake (253%), implying much better electrolyte wettability than the commercial polyolefin separator. In addition, the LIB integrated with PPS-mGNFs separator exhibits excellent discharge capacity, C-rate performance and cycling performance. This facile and promising strategy provides a platform for the large-scale fabrication of high-performance and safe LIB separators.

Lithium Difluorophosphate (LiPO2F2): An Electrolyte Additive to Help Boost Low-Temperature Behaviors for Lithium-Ion Batteries

A promising lithium salt of Li difluorophosphate (LiPO2F2) is introduced and added to the basic electrolyte (1 M LiPF6 + dimethyl carbonate (DMC)/ethyl methyl carbonate (EMC)/propylene carbonate (PC)/fluoroethylene carbonate (FEC)) to enhance the electrochemical performance of lithium-ion batteries by changing its concentration at low temperatures. Experiments show that LiPO2F2 can obviously improve the electrolyte’s ionic conductivity, especially. Compared with the baseline (6.29, 5.14, 4.62, 3.77, and 3.15 mS cm–1) under the same conditions, the ionic conductivities of the 2 wt % LiPO2F2-containing electrolyte (2 LiPO2F2) are 7.18, 5.32, 5.23, 4.04, and 3.57 mS cm–1. From this, it is clear that the integrated low-temperature electrochemical performances have been significantly improved. The specific discharge capacities of the 2 wt % LiPO2F2-added electrolyte at 0.2C are 161.4, 157.2, 148.9, and 137.5 mAh g–1 in the range from 25 to −40 °C, which are significantly much higher compared with the basic electrolyte (145.3, 149.4, 135.1, and 107.0 mAh g–1, respectively). Additionally, the addition of LiPO2F2 can promote profoundly the composition and morphology characteristics of the cathode–electrolyte interface (CEI) film; namely, it is a uneven lithium alkyl carboxylate before the addition of LiPO2F2; after that, it becomes an even LiF film, and meanwhile, the new film will facilitate Li+ transport in the electrolyte, further boosting the eletrochemical performance of the cells under low temperatures. At −40 °C under the same current density, the specific discharge capacity is 81.97 mAh g–1 after 50 cycles, while at the same temperature, the specific discharge capacity of the basic electrolyte battery is only 33.37 mAh g–1; that is, the discharge capacity has a staggering 145.6% improvement at −40 °C. In conclusion, the lithium-ion batteries containing LiPO2F2 may meet the application requirements of ultra-low-temperature conditions.

SnO2 nanoparticles composited with biomass N-doped carbon microspheres as low cost, environmentally friendly and high-performance anode material for sodium-ion and lithium-ion batteries

The oxygen vacancy-riched tin dioxide (SnO2) nanoparticles composites with biomass nitrogen-doped carbon microspheres (SNC composite materials) were fabricated to enhance the electrochemical performance of SnO2 as anode materials for sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs). The optimal SNC-2 electrode not only shows excellent electrochemical performance (reversible capacity of 557.1 mAh g−1 after 50 cycles at 0.05 A g−1, high-rate capability of 329.5 mAh g−1 and reversible capacity of 320 mAh g−1 after 1000 cycles even at a high current density of 1.0 A g−1) in SIBs, but also exhibits superior electrochemical performance in LIBs. Furthermore, ex-situ solid-state nuclear magnetic resonance (NMR) results (23Na, 19F and 119Sn MAS NMR spectra) reveal that the reversibility of the alloy NaxSn and SnO2, as well as the formation of NaF during the electrode reaction of SNC-2. The sodium peroxide (Na2O2) is probed by ex-situ solid-state NMR and ex-situ electron paramagnetic resonance (EPR) tests during the electrochemical process of SNC-2 electrodes for SIBs. An optimized reaction mechanism characterized by the formation of Na2O2 in SnO2 anodes for SIBs is proposed according to our work.

Phenyl Vinylsulfonate, a Novel Electrolyte Additive to Improve Electrochemical Performance of Lithium-Ion Batteries

Irreversible capacity fading, originating from the formation of the solid electrolyte interphase (SEI), is a common challenge encountered in lithium-ion batteries (LIBs) containing an electrolyte based on ethylene carbonate (EC). In this research, phenyl vinyl sulfonate (PVS) is examined as a novel electrolyte additive to mitigate this issue and subsequently enhance the cyclic stability of LIBs. As evidenced by density functional theory (DFT) calculations, PVS has a higher reduction potential than that of EC, which is in accordance with the cyclic voltammetry (CV) measurements. Accordingly, the PVS-containing electrolyte demonstrated a reduction peak at ~1.9 V, which was higher than that of the electrolyte without an additive (at ~1.7 V). In contrast to the SEI derived from the reference electrolyte, the one built-in PVS-containing electrolyte was capable of completely inhibiting the electrolyte reduction. In terms of the Raman spectroscopy and electrochemical impedance spectroscopy (EIS) analysis, SEI formation as the result of PVS reduction can lead to less structural disorder in the graphite electrode; the battery with the additive showed less interfacial and charge transfer resistance. The Li/graphite cell with 1 wt % of PVS delivered capacity retention much higher than that of its counterpart without the additive after 35 cycles at 1 C.

Effect of cation mixing of Li+/Ni2+ on heat generation of NCM811 cathode during long-term cycling at elevated temperature

The heat generation power of an electrode is one of the key factors affecting the operation safety and even the electrochemical performances of lithium-ion batteries. Herein, the heat generation power of a LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode at different cycling stages at an elevated temperature (50 °C) is studied. The internal and external factors, such as Li+ diffusion coefficient and Li+/Ni2+ cation mixing, affecting probably the heat generation are elaborated experimentally and theoretically. It is illustrated that the cation mixing of Li+/Ni2+ occurred during charge/discharge cycling reduces severely the diffusion coefficient of Li+ in NCM811 that accounts further for the increase in the as-generated heat amount and the heat generation power of the NCM811 with the cycling process.

Integrated pyrazine-based porous aromatic frameworks/carbon nanotube composite as cathode materials for aqueous zinc ion batteries

Aqueous zinc-ion batteries (ZIBs) have garnered intensive focus as a new generation of environmentally friendly and low-cost energy storage devices. However, the instability of the structure caused by Zn2+ insertion/extraction and slow kinetics limit its further development. Here, we proposed a rational strategy to link electroactive organic building blocks (HATN) using dual thioether bond and then in-situ polymerize it on carbon nanotube (CNT) (PAF-205/CNT). The extensive conjugated system constructed by sulfide chain and the introduction of conductive matrix can improve its conductive properties, thus increasing the utilization rate of active sites. As expected, PAF-205/CNT as the host material for zinc-ion storage shows a high initial capacity of 328.5 mA h g−1 at 50 mA g−1, a nearly 76.2 % capacity retention after 10,000 cycles at 20 A/g and a rate capacity of 89 mA h g−1 at 20 A/g. Furthermore, experimental analyses and theoretical calculation were performed to reveal the charge storage mechanism. Also, PAF-205/CNT cathode also shows good electrochemical performance in lithium-ion batteries (LIBs). Our study provides a strategy and insight for the rational design of promising organic electroactive materials for advanced metal-ion Batteries.

ZnS-PANI nanocomposite with enhanced electrochemical performances for lithium-ion batteries

ZnS-PANI nanocomposite with enhanced electrochemical performances for lithium-ion batteries

Monitoring the Electrochemical Capacitance By in Situ Impedance Spectroscopy As Indicator for Particle Cracking of (Nickel-Rich) Cathode Active Materials: Development of a Simplified Measurement Setup

Due to their high specific capacity, the market share of nickel-rich layered lithium nickel cobalt manganese oxides (NCMs, LiNixCoyMnzO2, x+y+z = 1) as cathode active materials (CAMs) for lithium-ion batteries is constantly growing. With higher nickel content, however, the increased capacity is often accompanied by shorter cycle life due to undesired side reactions on the CAM/electrolyte interface. As the optimization of the electrochemical performance of lithium-ion batteries by the adjustment of the composition of the cathode active materials has come to a limit, the focus has shifted to the modification of the morphological aspects. One way to minimize side reactions is to reduce the specific surface area of the CAM through a greater NCM crystallite size or through a customized particle morphology, both exhibiting less particle cracking upon charge/discharge cycling [1]. However, new methodologies for the quantification of aspects such as particle size, particle cracking, and surface area change are needed.Recently, we have developed a novel in situ analytical method which is able to quantify the increase of the CAM surface area upon extended charge/discharge cycling using electrochemical impedance spectroscopy (EIS) [2]. There, we make use of the direct correlation between the capacitance and the surface area of the electrode, whereby an increase of the capacitance indicates cracking of CAM particles, caused by the repeated volume change of the NCM material upon (de)lithiation and/or oxygen release at high state of charge [3]. In these works, the direct relationship between capacitance and NCM particle surface area was validated by ex situ krypton physisorption measurements.Unfortunately, this impedance-based method relies on a sophisticated experimental setup, using a micro-reference electrode (i.e., a gold-wire µ-RE) and a partially pre-lithiated lithium titanate (LTO) counter electrode. Therefore, in this study, we deduce a stepwise simplification of the capacitance measurements from the setup with a µ-RE and a pre-lithiated LTO counter electrode to a conventional coin half-cell setup, which is commonly used in industry for quick and routine material benchmarking. Additionally, it will be shown that the capacitance does not have to be extracted from a full impedance spectrum provided by an impedance analyzer, but that it can be obtained solely from a low-frequency single-point impedance measurement performed at a battery cycler. The working principle of this approach is validated using four different cell and potentiostat / battery cycler configurations over several charge/discharge cycles [4].The here demonstrated setup provides a simple method suitable for conventional coin half-cells to identify surface area changes of cathode active materials, being easily implemented in standard cycling procedures. Reference s [1] W. Li, E. M. Erickson, and A. Manthiram, Nature Energy 5 26 (2020).[2] S. Oswald, D. Pritzl, M. Wetjen, and H. A. Gasteiger, J. Electrochem. Soc. 167 100511 (2020).[3] S. Oswald, D. Pritzl, M. Wetjen, and H. A. Gasteiger, J . Electrochem . Soc . 168 120501 (2021).[4] S. Oswald, F. Riewald, H. A. Gasteiger, manuscript in preparation. Acknowledgements This work is financially supported by the BASF SE Network on Electrochemistry and Battery Research.