Performance Of Li-ion Batteries Research Articles

Synergy analysis on the heat dissipation performance of a battery pack under air cooling

Li-ion batteries are widely used for battery electric vehicles (BEV) and hybrid electric vehicles (HEV) due to their high energy and power density. A battery thermal management system is crucial to improve the performance, lifetime, and safety of Li-ion batteries. The research on the heat dissipation performance of the battery pack is the current research hotspot in the electric vehicle industry. In this paper, battery modules and battery pack are simplified to heat source and semi-closed chamber, respectively. The field synergy principle and CFD technology were used to make a synergy analysis on its heat dissipation performance. Thermal flow fields of different air outlet modes were considered in this paper, and the results show that the heat dissipation performance of air-cooled battery pack increases with the improvement of the synergy degree between velocity field and temperature gradient field. Compared with other air outlet modes, the upper air outlet mode has the best cooling effect, when the inlet air flow rate is 0.444 m/s, the maximum temperature rise and the maximum temperature difference of heat source can be controlled at 7.01 °C and 3.08 °C.

Lithium-Ion Battery Modeling Including Degradation Based on Single-Particle Approximations

This paper introduces a physical–chemical model that governs the lithium ion (Li-ion) battery performance. It starts from the model of battery life and moves forward with simplifications based on the single-particle model (SPM), until arriving at a more simplified and computationally fast model. On the other hand, the implementation of this model is developed through MATLAB. The goal is to characterize an Li-ion cell and obtain its charging and discharging curves with different current rates and different cycle depths, as well as its transitory response. In addition, the results provided are represented and compared, and different methods of estimating the state of the batteries are applied. They include the dynamics of the electrolyte and the effects of aging caused by a high number of charging and discharging cycles of the batteries. A complete comparison with the three-parameter method (TPM) is represented in order to demonstrate the superiority of the applied methodology.

TiO2-coated LiNi0.9Co0.08Al0.02O2 cathode materials with enhanced cycle performance for Li-ion batteries

Ni-rich cathode material is one of the most promising materials for Li-ion batteries in electric vehicles. However, fading capacity, poor cyclic stability and high pH value are still major challenges, which suppress its practical application. In this study, spherical LiNi0.9Co0.08Al0.02O2 powders with 0.4 wt% TiO2 coating layer were prepared by impregnation–hydrolysis method. Scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) results show that TiO2 is uniformly coated on the surface of LiNi0.9Co0.08Al0.02O2 particle and slightly embedded into LiNi0.9Co0.08Al0.02O2 particles. After 100 cycles at 2.0C, 0.4 wt% TiO2-coated LiNi0.9Co0.08Al0.02O2 electrode delivers much higher discharge capacity retention (77.0%) than the pristine LiNi0.9Co0.08Al0.02O2 electrode (63.3%). The excellent cycling performance of 0.4 wt% TiO2-coated LiNi0.9Co0.08Al0.02O2 electrode at a high discharge ratio is due to a TiO2 coating layer which can effectively reduce the direct contact between cathode material and electrolyte, suppress the oxidation of electrolyte, improve electrical conductivity of the electrode and increase the stability of the structure. With the increase of current density, TCNC sample clearly exhibits enhanced cycling performance with higher capacity retention, and the capacity retention of TCNC increases by 22% at 2.0 C.

Operando Identification of the Chemical and Structural Origin of Li-Ion Battery Aging at Near-Ambient Temperature.

Integrated with heat-generating devices, a Li-ion battery (LIB) often operates at 20-40 °C higher than the ordinary working temperature. Although macroscopic investigation of the thermal contribution has shown a significant reduction in the LIB performance, the molecular level structural and chemical origin of battery aging in a mild thermal environment has not been elucidated. On the basis of the combined experiments of the electrochemical measurements, Cs-corrected electron microscopy, and in situ analyses, we herein provide operando structural and chemical insights on how a mild thermal environment affects the overall battery performance using anatase TiO2 as a model intercalation compound. Interestingly, a mild thermal condition induces excess lithium intercalation even at near-ambient temperature (45 °C), which does not occur at the ordinary working temperature. The anomalous intercalation enables excess lithium storage in the first few cycles but exerts severe intracrystal stress, consequently cracking the crystal that leads to battery aging. Importantly, this mild thermal effect is accumulated upon cycling, resulting in irreversible capacity loss even after the thermal condition is removed. Battery aging at a high working temperature is universal in nearly all intercalation compounds, and therefore, it is significant to understand how the thermal condition contributes to battery aging for designing intercalation compounds for advanced battery electrode materials.

Mechanically Robust Tapioca Starch Composite Binder with Improved Ionic Conductivity for Sustainable Lithium-Ion Batteries

Binders have an important function in the performance of Li-ion batteries even though they are only used in small quantities. In addition to poor adhesion properties, the traditional polyvinylidene difluoride binder raises many environmental and health concerns because of their processing that involves hazardous organic solvents. In this study, we introduced a water-soluble, environmentally friendly tapioca starch binder modified with polyethylene glycol (PEG) groups as a novel binder for Si anode electrodes in Li-ion batteries. The experiments and density functional theory simulations indicate that abundant hydroxyl groups in the starch improve the binding strength with Si nanoparticles, and the integrated PEG groups facilitate Li-ion transfer in the Si electrode. The mechanical behavior of the electrode is significantly improved, as confirmed by nanoindentation and scratch tests. Excellent electrochemical performance is observed, with an initial lithiation capacity of 3486 mA h g-1 and a noteworthy second cycle capacity retention of 98%, demonstrating its potential as a cheap and sustainable binder for Li-ion batteries.

Nanostructured T-Nb2O5-based composite with reduced graphene oxide for improved performance lithium-ion battery anode

Nb2O5 has attracted much attention in various research filed such as hybrid capacitors, photo/electrocatalysis, and especially Li-ion batteries (LIBs) due to stable structure and high safety. Nevertheless, its low electronic conductivity (~ 3×10−6 S cm−1) degrades Li-storage performance that limits the practical use in LIBs. Here, we present a facile method for synthesis of T-Nb2O5 nanospheres/reduced graphene oxide composites by using niobium oxalate and bituminous coal as raw materials via a solvothermal method and subsequent calcination to enhance the conductivity of Nb2O5. In this work, the prepared Nb2O5 particles have excellent crystallinity that can be uniformly distributed onto the surface of the rGO layer to form Nb2O5/rGO composites. The electrochemical properties indicate that Nb2O5/rGO electrodes exhibit outstanding capacity, excellent reversibility, and superior cycle stability compared to other transition metal oxide-based electrodes. Notably, the initial capacities of the Nb2O5/rGO electrode at 0.02 A g−1 are 603 and 1104 mAh g−1, and the capacity still maintained 332 mAh g−1 after 100 cycles at 0.2 A g−1. Our synthetic approach provides a viable route to produce anode materials in a composite form facilitating nanostructured Nb2O5 with rGO exfoliated from bituminous coal for excellent performance in LIBs.

Experimental Study of the Performance of a Li-Ion Battery in a Highway Driving Cycle

Li-ion batteries, as a secondary battery type, are currently the most viable option for powering hybrid/electric vehicles. They have considerable advantages such as high specific energy and power, no memory effect, long cycling life, low maintenance requirement, and low self-discharge rate. However, their thermal performance can easily deteriorate at extreme ambient temperatures. Therefore, in this study, thermal and electrical behaviors of Li-ion batteries were investigated under various operating temperatures using a driving cycle that represents a highway driving condition. A battery testing system was used to determine the performance of Li-ion batteries under simulated loads. The results show that the measured temperature profiles, in broad strokes, follow the current profile. Because of the thermal capacitance of the battery, the changes in temperature variations are observed to be the smoothened out version of the current profile. Moreover, the results show that the extreme ambient temperatures have adverse effects on thermal performance of Li-ion batteries. The volumetric energy density and the capacity of the cell significantly decrease at cold ambient temperatures, especially for the sub-zero temperature applications possibly due to weak ionic conductivity within the cell. On the other hand, the difference between the ambient temperature and the surface of the cell becomes more pronounced as the ambient temperature decreases.

Interfacial kinetics induced phase separation enhancing low-temperature performance of lithium-ion batteries

Understanding the temperature dependence of phase transitions occurred in electrode materials is crucial for improving the low-temperature performance of Li-ion batteries. In this work, we find an unusual temperature dependence in the phase transition of TiO2 nanoparticles on dynamic Li+ intercalation, with a decrease in temperature resulting in the formation of a supersaturated solid solution phase. Kinetic analyses reveal that Li redistribution is facilitated at high temperature while limited at low temperature. This difference manifests as a thermodynamically-controlled phase separation at high temperature and a kinetically-controlled formation of a supersaturated solid solution phase at low temperature. Facilitating the phase separation by enhancing the interfacial kinetics proves effective to improve the low-temperature performance. This study provides a comprehensive and in-depth understanding of the temperature dependence of the lithiation-induced phase transition, which has important implications for the development of the next generation of all-climate rechargeable batteries.

Solid-electrolyte interphase nucleation and growth on carbonaceous negative electrodes for Li-ion batteries visualized with in situ atomic force microscopy

Li-ion battery performance and life cycle strongly depend on a passivation layer called solid-electrolyte interphase (SEI). Its structure and composition are studied in great details, while its formation process remains elusive due to difficulty of in situ measurements of battery electrodes. Here we provide a facile methodology for in situ atomic force microscopy (AFM) measurements of SEI formation on cross-sectioned composite battery electrodes allowing for direct observations of SEI formation on various types of carbonaceous negative electrode materials for Li-ion batteries. Using this approach, we observed SEI nucleation and growth on highly oriented pyrolytic graphite (HOPG), MesoCarbon MicroBeads (MCMB) graphite, and non-graphitizable amorphous carbon (hard carbon). Besides the details of the formation mechanism, the electrical and mechanical properties of the SEI layers were assessed. The comparative observations revealed that the electrode potentials for SEI formation differ depending on the nature of the electrode material, whereas the adhesion of SEI to the electrode surface clearly correlates with the surface roughness of the electrode. Finally, the same approach applied to a positive LiNi1/3Mn1/3Co1/3O2 electrode did not reveal any signature of cathodic SEI thus demonstrating fundamental differences in the stabilization mechanisms of the negative and positive electrodes in Li-ion batteries.

A Review of Pulsed Current Technique for Lithium-ion Batteries

Lithium-ion (Li-ion) batteries have been competitive in Electric Vehicles (EVs) due to their high energy density and long lifetime. However, there are still issues, which have to be solved, related to the fast-charging capability of EVs. The pulsed current charging technique is expected to improve the lifetime, charging speed, charging/discharging capacity, and the temperature rising of Li-ion batteries. However, the impact of the pulsed current parameters (i.e., frequency, duty cycle, and magnitude) on characteristics of Li-ion batteries has not been fully understood yet. This paper summarizes the existing pulsed current modes, which are positive Pulsed Current Mode (PPC) and its five extended modes, and Negative Pulsed Current (NPC) mode and its three extended modes. An overview of the impact of pulsed current techniques on the performance of Li-ion batteries is presented. Then the main impact factors of the PPC strategy and the NPC strategy are analyzed and discussed. The weight of these impact factors on lifetime, charging speed, charging/discharging capacity, and the temperature rising of batteries is presented, which provides guidance to design advanced charging/discharging strategies as well as to determine future research gaps.

Interactions and Transport in Highly Concentrated LiTFSI-based Electrolytes.

To elucidate what properties control and practically limit ion transport in highly concentrated electrolytes (HCEs), the viscosity, ionic conductivity, ionicity, and transport numbers were studied for nine model electrolytes and connected to the rate capability in Li-ion battery (LIB) cells. The electrolytes employed the LiTFSI salt in three molar ratio concentrations; 1 : 2, 1 : 4, and 1 : 16 (LiTFSI:X) vs. solvents (X) with different permittivities; tert-butyl methyl ether (MTBE), tetrahydrofuran (THF) and propylene carbonate (PC). While the low polarity MTBE creates liquid electrolytes, ion-pairing limits the ionic conductivity despite extremely low viscosities. For the less concentrated 1 : 16 LiTFSI:MTBE and 1 : 16 LiTFSI:THF electrolytes the ionic diffusivities decrease with increased temperature, a sign of aggregation, but still their ionic conductivities and LIB performance increase. In general, the low ionic conductivity and high viscosity both limit the use of HCEs in LIBs, and no compensating mechanism seems to be present.

On the Importance of Incorporating Structural Heterogeneity of Porous Electrodes in LI-ION Battery Models: Pore Network Modelling a Way to MOVE Forward

Image processing of 3D tomographic images to extract structural information of porous materials has become extremely important in porous media research with the commoditization of x-ray tomography equipment to the lab scale. Extracted pore networks from image analysis techniques enable transport properties calculation for bigger domains at a very low computational cost, allowing substantial investigation of porous media. Consequently, they are being increasingly used to model Multiphysics transport processes in various energy storage devices like fuel cells and batteries, where the geometrical structure plays a vital role in electrochemical performance, but true pore-scale modeling is computationally infeasible.Traditionally, pore network modelling has been used to find electrochemical performance of Li Ion batteries by investigating pore phase interconnectivity in carbon electrodes. The actual lithium ion electrode, however, consists of active material, carbon binder and electrolyte filled pore phase. The interconnectivity of these phases influences the effective transport properties and hence electrochemical performance of cathode material. The presence of carbon binder phase not only reduces the SEI layer between active material and electrolyte phase but also influences tortuosity and effective electronic conductivity in the pore and solid phase respectively. The present work uses a pore network modelling frame work to investigate the effect of carbon binder phase on Lithium Ion battery cathode. We used actual three phase, X-ray tomography image of NMC-811 cathode material and studied its electrochemical performance with and without binder phase. Unlike previous models which compensate the importance of carbon binder as electrical conductor by assuming high electronic conductivity of active material, this study considers actual values of conductivities in all phases. Moreover, the impact of nanoporosity in the carbon binder phase was also explored and found to enhance the reaction rate compared to solid binder. The reduction in computational time achieved using the pore-network approach was so significant that adding additional physics and transient conditions could conceivably be included to increase the accuracy of the model, thereby providing more realistic simulations and point to the true limiting processes. The developed pore network model opens a new avenue for modelling complex electrochemical systems with less computational cost, enabling simulation of bigger electrode domains while keeping structural heterogeneities of material.

Deciphering the Role of Temperature and Thermal Gradient Magnitude on Li-Ion Battery Performance and Safety

Lithium-ion batteries are a transformative technology that have far-reaching implications in applications from consumer electronics to vehicles. The transient environmental conditions of many of these applications combined with internal heat generation and removal from the battery during operation cause it to be subjected to various thermal profiles. It has been shown that the cell’s material properties and kinetics are temperature dependent [1-3] and that thermal gradients can modulate electrochemistry [4, 5]. Our prior studies of externally-applied thermal gradients in batteries found that a gradient of 40 °C across the cell (0 °C anode-side and 40 °C cathode-side) has profound effects on local electrochemistry. However, the sensitivity of the cell to varied local electrode temperatures and the magnitude of the anode-to-cathode thermal gradient remains uncertain. In this work, we decipher the contributions of these two thermal aspects by independently modulating the temperature of each electrode within a single-layer pouch cell. Li-ion full cells are fabricated using lithium-iron-phosphate cathodes and graphite anodes. Local temperature measurements of the electrodes are obtained using thin-film sensors embedded within the cell. Galvanostatic cycling at different current rates and electrochemical impedance spectroscopy are performed on cells with various temperature and thermal gradient magnitudes to quantify thermo-electrochemical coupling phenomena. The implications of the thermal and operating conditions on battery performance and safety are discussed. This work demonstrates the need for effective thermal management strategies that can enable desired operational conditions, such as fast charging, while maintaining safe operation.

Designs of Experiments to Optimize Li-Ion Batteries

Studies pinpointed the limitation of power-related performance for Li-ion batteries to the microstructure of each electrode.1, 2 This random arrangement of the active material (AM) and carbon filling particles bound by a polymer is typically characterized through physical values such as tortuosity, porosity and Mac Mullin Number.3 There is nonetheless no consensus on what the best formulation is for a given set of electrode components.The relationship between microstructure and performance is investigated by planning and analyzing a Design of Experiments based on a Complex Mixture Design. Thirty different formulations were characterized where Li4Ti5O12 was the AM, and carbon black and carbon nanofibers were conductive fillers. As for the binder, two were studied: polyvinylidene fluoride and a fluorine-free thermoplastic elastomer.4 All other factors, e.g. rheology or experimenter bias, were closely monitored and finely controlled to remain identical for all samples.Electrochemical performance were studied at low, medium and high charging speeds to account for different limitations of full capacity retention. Statistical analysis showed clear correlations between the formulation and the electrodes’ capacity with very high descriptive statistics, e.g. R2. Lastly, strong correlations were found between capacity and microstructure, strengthening further the trust in the empirical equations. These robust models helped choosing optimal fluorine-free formulations that surpassed even the highest performing previous electrodes. 1. Vasileiadis, A.; Klerk, N. J. J. d.; Smith, R. B.; Ganapathy, S.; Harks, P. P. R. M. L.; Bazant, M. Z.; Wagemaker, M., Toward Optimal Performance and In‐Depth Understanding of Spinel Li4Ti5O12 Electrodes through Phase Field Modeling. Advanced Functional Materials 2018, 0 (0), 1705992.2. Ngandjong, A. C.; Rucci, A.; Maiza, M.; Shukla, G.; Vazquez-Arenas, J.; Franco, A. A., Multiscale Simulation Platform Linking Lithium Ion Battery Electrode Fabrication Process with Performance at the Cell Level. The Journal of Physical Chemistry Letters 2017, 8 (23), 5966-5972.3. Landesfeind, J.; Hattendorff, J.; Ehrl, A.; Wall, W. A.; Gasteiger, H. A., Tortuosity Determination of Battery Electrodes and Separators by Impedance Spectroscopy. Journal of The Electrochemical Society 2016, 163 (7), A1373-A1387.4. Rynne, O.; Lepage, D.; Aymé-Perrot, D.; Rochefort, D.; Dollé, M., Application of a Commercially-Available Fluorine-Free Thermoplastic Elastomer as a Binder for High-Power Li-Ion Battery Electrodes. Journal of The Electrochemical Society 2019, 166 (6), A1140-A1146.With this presentation, we want to show the versatility and power of Designs of Experiments to the community, whether for electrode formulation or new material synthesis, as the input parameters can be easily interchangeable. Figure 1

Design of P-Doped Mesoporous Carbon Nitrides as High-Performance Anode Materials for Li-Ion Battery.

Herein, we demonstrate a simple and unique strategy for the preparation of P-doped into the substructure of mesoporous carbon nitride materials (P-MCN-1) with ordered porous structures as a high-energy and high-power Li-ion battery (LIB) anode. The P-MCN-1 as an anode in LIB delivers a high reversible discharge capacity of 963 mAh g-1 even after 1000 cycles at a current density of 1 A g-1, which is much higher than that of other counterparts comprising s-triazine (C3H3N3, g-C3N4), pristine MCN-1, and B-containing MCN-1 (B-MCN-1) subunits or carbon allotropes like CNT and graphene (rGO) materials. The P-MCN-1 electrode also exhibits exceptional rate capability even at high current densities of 5, 10, and 20 A g-1 delivering 685, 539, and 274 mAh g-1, respectively, after 2500 cycles. The high electrical conductivity and Li-ion diffusivity (D), estimated from electrochemical impedance spectra (EIS), very well support the extraordinary electrochemical performance of the P-MCN-1. Higher formation energy, lower bandgap value, and high Li-ion adsorption ability predicted by first principle calculations of P-MCN-1 are in good agreement with experimentally observed high lithium storage, stable cycle life, high power capability, and minimal irreversible capacity (IRC) loss. To the best of our knowledge, it is an entirely new material with the combination of ordered mesostructures with P codoping in carbon nitride substructure which offers superior performance for LIB, and hence we believe that this work will create new momentum for the design and development of clean energy storage devices.

Constructing three-dimensional Li-transport channels within the Fe3O4@SiO2@RGO composite to improve its electrochemical performance in Li-ion batteries

Magnetite Fe3O4 particles are usually pulverized when used as the anode material for Li-ion batteries and thus the solid electrolyte interface film grows on the surface progressively, leading to inferior cycling performance and poor rate capability. To solve these issues, core-shell Fe3O4@SiO2 particles are wrapped by reduced graphene oxide (RGO), and meso-/micro-pores are produced not only in the SiO2 layers but also in the RGO nanosheets by chemical etching, forming three-dimensional (3D) continuous channels for Li+ transportation. Benefiting from this unique structure, the as-prepared Fe3O4@mSiO2@RGO composite can deliver a capacity of 1630 mA h g−1 at 0.1 A g−1 over the potential range of 0.01–3.00 V (vs. Li+/Li) in the first discharge along with an initial coulombic efficiency of 86%, and can retain the capacity of 514 mA h g−1 at 5 A g−1 after 1000 cycles, exhibiting an outstanding rate capability and a long-term span life. The results indicate that pseudocapacitive behavior enables this composite to charge/discharge fast while the porous SiO2 shell and RGO nanosheets effectively accommodate the volume change of the Fe3O4 particles during cycling. Our findings provide a feasible strategy for improving the electrochemical properties of the Fe3O4 anode in Li-ion batteries.

A density functional theory study of high-performance pre-lithiated MS2 (M\u2009=\u2009Mo, W, V) Monolayers as the Anode Material of Lithium Ion Batteries

Recent experimental study shows that the pre-lithiated MoS2 monolayer exhibits an enhanced electrochemical performance, coulombic efficiency of which is 26% higher than the pristine MoS2 based anode. The underlying mechanism of such significant enhancement, however, has not yet been addressed. By means of density functional theory (DFT) calculations, we systematically investigated the adsorption and diffusion behavior of lithium (Li) atoms on the MS2 (M = Mo, W, V) monolayers. On the pre-lithiated MS2 monolayers, the adsorption energy of extra Li ions are not significantly changed, implying the feasibility of multilayer adsorption. Of importance, the Li diffusion barriers on pre-lithiated MS2 are negligibly small because of the charge accumulation between the diffusing Li ions and the pre-lithiating Li layer. Correspondingly, we report that the pre-lithiation should be a general treatment which can be employed on many transition-metal di-chalcogenides to improve their storage capacities and charge-discharge performance in Li ion batteries. In addition, we propose that the pre-lithiated VS2 may serve as an outstanding anode material in LIBs.

Accelerated Optimization Methods for Force‐Field Parametrization in Battery Electrode Manufacturing Modeling

AbstractThe performance, durability and cost of modern Li‐ion batteries (LIBs) strongly depend on their manufacturing process. In this regard, computational methods that attempt to model LIBs manufacturing have the potential to help experimentalists to reduce costs and improve performances of LIBs. To do so, the electrode slurry phase, consisting of a suspension of active material, carbon additive and binder in a solvent must be modeled at first at the mesoscopic scale. However, efforts in that sense are rare in literature due to the inherent complexity of slurries and the difficulty of setting up appropriate metrics for the validation of the modeling results. For the first time, we propose an approach relying on experimental data that allows to validate the properties of simulated Nickel‐Manganese‐Cobalt‐based slurries with different compositions and solid contents through force fields (FFs) parametrization. The latter was attained by Coarse‐Grained Molecular Dynamics (CGMD), which enables to model the slurry phase at the mesoscopic scale and to consider explicitly the carbon binder domain. Moreover, we demonstrate that the CGMD FFs parameterization can be accelerated thanks to different types of Particle Swarm Optimization‐based algorithms, which would allow faster screening of different simulated slurries fabrication conditions.

Li-Ion Battery Performance Degradation Modeling for the Optimal Design and Energy Management of Electrified Propulsion Systems

Heavy-duty hybrid electric vehicles and marine vessels need a sizeable electric energy storage system (ESS). The size and energy management strategy (EMS) of the ESS affects the system performance, cost, emissions, and safety. Traditional power-demand-based and fuel-economy-driven ESS sizing and energy management has often led to shortened battery cycle life and higher replacement costs. To consider minimizing the total lifecycle cost (LCC) of hybrid electric propulsion systems, the battery performance degradation and the life prediction model is a critical element in the optimal design process. In this work, a new Li-ion battery (LIB) performance degradation model is introduced based on a large set of cycling experiment data on LiFePO4 (LFP) batteries to predict their capacity decay, resistance increase and the remaining cycle life under various use patterns. Critical parameters of the semi-empirical, amended equivalent circuit model were identified using least-square fitting. The model is used to calculate the investment, operation, replacement and recycling costs of the battery ESS over its lifetime. Validation of the model is made using battery cycling experimental data. The new LFP battery performance degradation model is used in optimizing the sizes of the key hybrid electric powertrain component of an electrified ferry ship with the minimum overall LCC. The optimization result presents a 12 percent improvement over the traditional power demand-driven hybrid powertrain design method. The research supports optimal sizing and EMS development of hybrid electric vehicles and vessels to achieve minimum lifecycle costs.

Molybdenum-Tellurite Oxide Glass: Synthesis and Applications for Lithium-Ion Batteries and Zn-Air Batteries

In this work, MoO3-TeO2 (MT) glasses are synthesized (xMoO3-100-xTeO2, in mol.%) by a simple melt-quenching method. It is found that the MT glass exhibits high specific capacities, significantly improved cycling performance for Li-ion batteries and catalytic activity when applied in Zn-air batteries. The 30%MoO3-70%TeO2 glass (MT30) shows a stable capacity of 124.4 mAh g−1 at a high current density of 5 A g−1 after 5000 cycles. The MT glass is accompanied by a crystallization process during discharge/charge cycles. The precipitated nanocrystals are uniformly dispersed in the MT glass matrix to form an ordered/disordered structure. It is also found that Li2MoO4 nanocrystal formed in glass matrix during the charge/discharge cycles. The newly formed homogeneous nanocrystal dispersed in glass matrix can enhance the conductivity and Li+ diffusion coefficient of glass materials. This kind of structure can restrain the volume expansion during the Li+ insertion/extraction. Furthermore, when used as a cathode catalyst for Zn-air batteries, the performance of the MT30 is maintained for 35 h under a current density of 5 mA cm−2, showing long-term cycling stability. This work reports the application of glass materials in catalysis, which will provide a scheme for developing glass-based energy storage materials.