Advanced Lithium-ion Batteries Research Articles

Constructing a robust integrated surface structure for enhancing the performance of Li-rich Mn-based oxides cathodes

Li-rich Mn-based oxides (LRMO) have emerged as the next-generation cathode materials for the advanced lithium-ion batteries due to its high capacity and low cost. However, its practical application has been impeded by the irreversible oxygen loss and structural deterioration of LRMO surface, resulting in low initial coulombic efficiency (ICE), capacity, and voltage degradation as well as sluggish kinetic reaction. Herein, we present a surface engineering strategy that uses NH4BF4 treatment to simultaneously integrate spinel phase, oxygen vacancies, and dual-element (B and F) doping on the LRMO surface. As a consequence, the treated LRMO, namely NHBF-2, shows much higher ICE of 89.41% with an increased capacity retention of 88.9% at 1 C after 100 cycles than the untreated LRMO (76.87% and 79.6% for ICE and capacity retention, respectively). Such improved performance of LRMO can be attributed to the robust integrated surface, where oxygen vacancies remove surface labile oxygen and suppress irreversible oxygen releasing, spinel phase promotes the Li+ diffusion kinetic, and B and F doping aids in stabilizing the surface structure. This study provides guidance for designing high-energy cathode materials with a stable surface by using surface modification on LRMO.

A facile assembly of SnO2 nanoparticles and moderately exfoliated graphite for advanced lithium-ion battery anode

High-capacity SnO2 is considered as one of the most potential anode candidates but suffers from its low coulombic efficiency, low conductivity, and large volume expansion. To solve these bottlenecks, we designed an assembly of nano-SnO2 and moderately exfoliated graphite (MEG) to form a hybrid of SnO2 and MEG coated with amorphous carbon (SnO2/MEG@C). In the liquid phase system at room temperature, the moderate exfoliation of graphite and the SnO2 embedded into the MEG interlayer were realized at the same time. Graphite expansion generates plenty of parallel lamellas, which accommodates the SnO2 nanoparticles between these lamellas and prevents their agglomeration in confined spaces. The MEG as flexible and conductive support can attach SnO2 nanoparticles tightly, which enhance the electron transfer, and also can hinder the agglomeration of SnO2. Meanwhile, the carbon coating can effectively adapt to the volume changes of SnO2 nanoparticles. Moreover, the interaction between the MEG and carbon coating can form a physical barrier that effectively hinders Sn coarsening, which maintains the rapid mutual diffusion kinetics between nano Sn/Li2O interfaces, leading to the high-efficiency conversion reaction of SnO2 in the composite and excellent reversibility and cyclicity. The SnO2/ MEG@C electrode exhibits a high capacity of 691.4 mAh g−1 after 900 cycles at 1.0 A g−1. The method in this work can guide the design and synthesis of materials with high capacity and adaptive volume expansion.

Facile synthesis of yolk-shell CoS2@FeS2@NC hollow microspheres for advanced lithium-ion batteries anode materials

Facile synthesis of yolk-shell CoS2@FeS2@NC hollow microspheres for advanced lithium-ion batteries anode materials

Heterostructured FeS2/SnS2 nanoparticles anchored on graphene for advanced lithium and sodium-ion batteries

SnS2 is intensively investigated as a prospective anode for lithium and sodium-ion batteries (LIBs and SIBs), owing to its high capacity, large interlayer distance, and low redox potentials. Nevertheless, the dramatic volume variation, and inferior electrical conductivity upon discharge/charge process, resulted in poor cycling and rate performance. Herein, a heterostructured binary sulfide (FeS2/SnS2) nanoparticles coated with N-doped carbon and further wrapped with graphene (FSS@NC/rGO) is synthesized by a facile co-precipitation method coupled with PDA coating and in-situ sulfidation process. The heterostructure FeS2/SnS2 greatly accelerates the ion/electron transport, as well as keeps a stable structure during the cycling process. Meanwhile, the N-doped carbon and graphene matrix enable good electrical conductivity, as well as accommodate the volume variation during the cycling process. Accordingly, the FSS@NC/rGO displays a fantastic capacity (1192.2 mAh/g at 0.2 A/g), outstanding rate performance (499.5 mAh/g at 5.0 A/g), and long-cycle stability (724.9 mAh/g at 2 A/g after 500 loops) in LIBs. Meanwhile, the FSS@NC/rGO delivers a high Na-storage capacity of 451.8 mAh/g after 200 loops at 0.2 A/g.

Nanoscale surface modification to suppress capacity fade of Ni-Rich layered oxide material at high cut-off voltage

Ni-rich layered oxide is a promising cathode material for future advanced lithium-ion batteries (LIBs). However, the nickel-rich layered cathode material exhibits insufficient high-voltage cycling stability ascribing to the phase transformation, surface side reactions, and lattice oxygen evolution. This work developed an effective inorganic coating strategy to construct LiNiO2/Na1-xNi1-yPO4 surface hybrid coating layer and Na bulk doping simultaneously by a simple wet-chemical method, improving the high-voltage performance of LiNi0.8Co0.1Mn0.1O2 (NCM) effectively. It is found that the surface oxygen vacancy and surface residual lithium on NCM reacts with NaNiPO4 precursors at 500 °C to form LiNiO2 inner layer in addition to the Na1-xNi1-yPO4 outer layer, which is structurally coherent to the layered lattice of NCM. In the constructed hybrid layer, layered phase LiNiO2 firmly fixes on the NCM surface. At the same time, highly chemical stable Na1-xNi1-yPO4 with lattice tunnels can enable lithium-ion transport and act as a protecting layer to inhibit surface side reactions. In addition, Na bulk doping could enlarge lithium-ion diffusion channels and stabilize lattice structure. All these advantages contribute to improving the electrochemical performance of NCM. The results show that the surface treatment NCM cathode exhibit excellent cycling stability with a higher capacity retention of 88 % after 200 cycles under 25 °C and 86 % after 100 cycles under 55 °C, both at 1C. This method provides a feasible strategy to promote the high-voltage cycling performance of electrode material, thus improving the service life, energy density, and safety performance of Li-ion batteries.

Safe solid-state PEO/TPU/LLZO nano network polymer composite gel electrolyte for solid state lithium batteries

Herein, Li7La3Zr2O12 (LLZO) ceramic nano-networks were introduced by electrostatic spinning into the polyethylene oxide (PEO)/thermoplastic polyurethane (TPU)/LiTFSI matrix (PTL) to constitute novel composite solid electrolytes due to the synergy between the nano-networks and the electrolyte matrix. By adjusting the LLZO nanonetwork with different weight ratios (5 wt%, 10 wt%, and 15 wt%) relative to the total weight of the PEO/TPU/LiTFSI/LLZO (PTLL) composite electrolyte, the electrochemical behavior of the gel electrolyte was optimized. When filled with a 10 wt% Li7La3Zr2O12 nano-network, the PTLL has a maximum ionic conductivity of 1.33 × 10−3 S cm−1 at 60 °C and an electrochemical stability window of 5.6 V. Furthermore, the LiFePO4/PTLL/Li battery presents an initial specific discharge capacity of 170 mA h g−1 at 0.1 C. After 100 cycles, it demonstrated superior cycle durability at 0.5 C at 60 °C, representing 96.1 % of the initial capacity. These results indicate that the PTLL electrolyte is a promising candidate for advanced solid state lithium batteries.

Insight into the cation migration and surface structural evolution of spinel LiNi0.5Mn1.5O4 cathode material for lithium-ion batteries

High-voltage spinel LiNi0.5Mn1.5O4 (LNMO) is considered to be a promising cathode material for electric vehicles (EV) and hybrid electric vehicles (HEVs). Nevertheless, the structural transformation under a deep discharge voltage is still ambiguity. Herein, we report detailed studies of structural change of LNMO cathode under a wide voltage range of 5.0–1.5 V cycling by using synchrotron-based X-ray absorption spectroscopy, aberration-corrected scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS). The fundamental findings demonstrate that LNMO would undergo a complex phase transformation from cubic to tetragonal during deep discharge to a voltage lower than 3 V. It gives rise to a further reduction of Mn4+ to Mn3+ and this serious structural distortion leads to the formation of Li2Mn2O4-type tetragonal phase with space group of I41/amd, which is also confirmed by XANES simulations and density functional theory (DFT) calculations. Meanwhile, migration of Ni ions toward the surface from bulk lattice, leading to the rock-salt NiO phase formation with a space group of Fm-3 m. Finally, these observed evolutions on the surface are associated to the fast capacity fading for LNMO under such a wide voltage range. This work provides insight into understanding the capacity degradation mechanism of spinel cathodes and would inspire us to further design high-performance cathode materials for advanced lithium-ion batteries.

Additive manufacturing for advanced rechargeable lithium batteries: A mini review

Additive manufacturing techniques have shown great promise in changing the way batteries can be designed due to their excellent geometry controllability, process flexibility and high sustainability in manufacturing complex-shaped structures, which have been progressively applied in design of high-performance lithium batteries. In this review, the latest advances in 3D printed lithium batteries have been summarized with a focus on the fundamentals of representative additive manufacturing techniques involving the operation mechanisms, manufacturing accuracy, respective advantages and challenges. In addition, the general 3D printing design principles in module architectures, materials selection and battery configurations for developing high performance lithium batteries are also systematically discussed. Finally, pertinent insights into the future perspectives of 3D printed lithium batteries have been emphasized, expecting to enlighten the research directions of practical applications of 3D printed batteries.

Corn-like Si derived from sepiolite as anode for advanced lithium-ion batteries

Low initial coulombic efficiency (ICE) and poor long-term cycling performance are key issues of silicon (Si) anode for lithium-ion batteries (LIBs), due to the irreversible consumption of Li ion. Herein, Si with corn-like structure is synthesized by a simple and low cost magnesiothermic reduction method from pre-treated sepiolite ore. The ICE of corn-like Si reaches 75.1 % and can be increased to almost 100 % by a simple surface prelithiated engineering, meanwhile the charge capacity remains 788 mA h·g-1 (0.56 mAh·cm-2) after 500 cycles at 1 A·g-1(0.71 mA·cm-2). Further SEM observation reveals that the prelithiated Si electrode keeps the original corn-like structure during cycling, confirming that available-Si from natural clay is applicable for the production of LIBs.

Industrial modification comparison of Ni-Rich cathode materials towards enhanced surface chemical stability against ambient air for advanced lithium-ion batteries

Ni-rich layered oxides (e.g. LiNi0.8Co0.1Mn0.1O2, denoted as NCM811) with high capacity and moderate cost are promising cathodes for high energy density Li-ion batteries. However, the highly chemical sensitivity to H2O and CO2 triggers the serious surface degradation when exposed to ambient air, which becomes an intractable obstacle for the large-scale production and application of Ni-rich cathodes. Herein, we comprehensively evaluate the effects of three industrial treatment strategies, including washing, washing–reheating, and washing–boron oxide coating–reheating, on the air stability, slurry processability and electrochemical performance of NCM811 cathodes. It is demonstrated that the slurry processability can be greatly improved by water washing. However, water washing leads to more inferior air stability, which can be restored via a post-heating treatment. Impressively, with the aid of B2O3 protective coating nanolayer, the thickening of surface degradation-induced passive layers is significantly suppressed that effectively prevents the detrimental surface phase transformation, thereby extending the ambient storage life and avoiding the slurry gelation. More importantly, B2O3 coated NCM811 cathode exhibits the low interfacial reaction resistance and excellent cyclic stability even after 8 weeks air exposure. This work paves the road for the industrial surface treatment of Ni-rich cathode materials, and deepens the understanding of surface stabilization mechanisms under practical application conditions.

In-situ synthesis of reduced graphene oxide wrapped Mn3O4 nanocomposite as anode materials for high-performance lithium-ion batteries

We report a novel in-situ symbiosis method to prepare reduced graphene oxide wrapped Mn3O4 nanoparticles (rGO/Mn3O4) with uniform size about 50 nm as anodes for lithium-ion batteries (LIBs), which can simplify the preparation process and effectively reduce pollution. The rGO/Mn3O4 nanocomposite exhibited a reversible specific capacity of 795.5 mAh g−1 at 100 mA g−1 after 200 cycles (capacity retention: 87.4%), which benefits from the unique structural advantages and the synergistic effect of rGO and Mn3O4. The Mn3O4 nanoparticles encapsulated among the rGO nanosheets exhibited good electrochemical activity, and the multilayer wrinkled rGO sheets provided a stable 3D conduction channel for Li+/e− transport. The rGO/Mn3O4 nanocomposite is a promising anode candidate for advanced LIBs with excellent cycling performance and rate performance. Furthermore, this new preparation method can be extended to green and economical synthesis of advanced graphene/manganese-based nanocomposites.

Tuning Interphase Chemistry to Stabilize High-Voltage LiCoO2 Cathode Material via Spinel Coating.

Cathode electrolyte interphases (CEIs) are critical to the cycling stability of high-voltage cathodes for batteries, yet their formation mechanism and properties remain elusive. Here we report that the compositions of CEIs are largely controlled by abundant species in the inner Helmholtz layer (IHL) and can be tuned from material aspects. The IHL of LiCoO2 (LCO) was found to alter after charging, with a solvent-rich environment that results in fragile organic-rich CEIs. By passivated spinel Li4 Mn5 O12 coating, we achieve an anion-rich IHL after charging, thus enabling robust LiF-rich CEIs. In situ microscopy reveals that LiF-rich CEIs maintain mechanical integrity at 500 °C, in sharp contrast to organic-rich CEIs which undergo severe expansion and subsequent voids/cracks in the cathode. As a result, the spinel-coated LCO exhibits a high specific capacity of 194 mAh g-1 at 0.05 C and a capacity retention of 83 % after 300 cycles at 0.5 C. Our work sheds new light on modulating CEIs for advanced lithium-ion batteries.

High-voltage operation by mechanical interlocking adhesion of nickel-rich cathode and functional separator in lithium-ion batteries

High-voltage operating is an effective route to provide upgrading the energy density of advanced lithium-ion batteries (LIBs). However, detrimental capacity decay caused by the high-voltage cycling makes it difficult to obtain stable long-term operation. Use of electrolyte additive can suppress fast capacity decay, but the prolonged effectiveness is hindered by the increased gaseous product at the electrode. In this work, we apply a functional separator having an adhesive layer on the ceramic-coated separator in high-voltage operating LIB. Mechanical interlocking adhesion between the electrode and separator prevents delamination resulting in high-capacity retention during the 500 charge–discharge cycles with the cut-off voltage of 4.5 V even with the reactive vinylene carbonate additive. This was evidenced by the X-ray inspection designed for the detection of gas pockets in pouch cells, caused by the continuous gas pressure build-up during the early cycles. Results indicate that the suppression of the gas pocket led to the prevention of capacity decay and provided a powerful strategy to extend the effect of increasing operating voltage. The approaches in this study not only highlight the importance of mechanical interlocking between the electrode and separator but also present insights into the electrode interfaces, which are still not fully understood.

Galvanically Displaced Noble Metal Nanoparticles Onto Electrosprayed Graphene-CNT Electrodes for Lithium-Ion and Fuel Cell Applications

Advanced lithium-ion batteries (LIB) and Fuel Cells demonstrate promise as the next generation energy storage and conversion (ESC) technology especially as it pertains to wearable technology and electric vehicles. Although LIB dominate the battery market (>90%) due its reliability, long cycle life, and market maturity, different and more innovative ways to improve the chemistry of the electrode structure must be discovered in order to reduce the cost of materials, dendritic issues at the solid-electrolyte interphase (SEI) layer, and improve upon the limited anode capacity (graphite theoretical capacity 372 mAh g-1). Fuel cells are also promising renewable energy sources due to their high energy densities and scalability. However, both LIB and Fuel Cells are limited by the 3D materials that enable their enhanced electrochemical and catalytic performance. We propose a platform methodology for the synthesis of 3D electrodes with carbon nanomaterials and noble metals. The enhanced electrical, thermal, chemical, and mechanical stability of graphene and carbon nanotubes (CNTs) offer an ideal platform for electrode design for energy storage applications. Here we utilize spontaneous galvanic displacement driven by reduction potential difference to produce three-dimensional (3D) graphene-CNT-noble metal nanoparticle 3D electrode without the use of any harsh chemical reducing agents. A graphene-CNT slurry with a poly(acrylic acid) (PAA) binder is air-controlled electrosprayed onto copper foil to create 3D composite thin film electrodes. Although noble metals are expensive materials to be used in LIB, we propose a new approach for synthesizing conductive electrochemically stable electrodes. We demonstrate a spontaneous technique to reduce the noble metal salts by galvanically displacement with the copper substrate to deposit noble metal nanoparticles onto the graphene-CNT electrode. The noble metal salt solutions (HAuCl4, K2PtCl4, and Na2PdCl4) are drop casted onto the resulting copper supported graphene-CNT electrodes to enable electroless noble metal nanoparticle deposition. Scanning electron microscopy (SEM) imaging confirms that the carbon nanomaterials are integrated with noble metal nanoparticles forming an overall 3D electrode structure. Raman spectroscopy verifies the characteristic D-band, G-band, and 2D-band peaks from the graphitic structure within the 3D carbon and noble metal nanostructure. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) are used to characterize the electrochemical properties of the electrodes. We demonstrate that the use of an energy-free and spontaneous process based on the difference in thermodynamic reduction potentials as the driving force for producing carbon nanomaterial/noble metal nanostructured electrodes for batteries and fuel cells. This process is a more simple, scalable, and cost-efficient alternative to current methods for developing lightweight and catalytic electrodes for energy storage applications, such as lithium-ion batteries, lithium-air batteries, and fuel cells. Raman Spectroscopy is used to confirm the presence defects on the oxidized carbon nanotube and graphene oxide surface. Scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), and x-ray diffraction (XRD) were used to characterize the morphology of the 3D carbon-noble metal structure and the surface elemental composition. Electrochemical characterization techniques such as electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), performance testing for oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and potentiostatic measurements are used to characterize the areal specific resistance (ASR), areal capacitance, electrochemical surface area, initial Coulombic efficiency (ICE), rate capability and cycling performance, and electrochemical stability, respectively.

Investigation of Garnet Solid Electrolyte-Layered Oxide Cathode Interfaces Towards Cylindrical High-Performance Li-Ion Batteries

Even though the Ni-rich cathode materials (Ni content > 60%), providing high energy density and high capacity, can draw much attention for advanced lithium-ion battery (LIB) community and industry, several drawbacks such as poor structural stability, thermal stability, and capacity fading still restrict their scalable application. Herein, the trace amount of garnet Li7La3Zr2O12 (LLZO) oxide solid-state electrolyte was introduced on the LiNi0.8Mn 0.1 Co0.1O2 (NMC811) cathode as a scaffolding interfacial layer on NMC particles via a one-step solvent-free mechanofusion process. The interfacial La-Ni exchange after mechanofusion was investigated by the extended X-ray absorption fine structure (EXAFS) measurement. Subsequently, the in situ X-ray diffraction was used to investigate the crystallographic evolution during the charge-discharge process. The NMC-LLZO cathode exhibits excellent rate capability and cycling performance, especially at high current density. The LLZO interfacial layer was found to be able to delay Li insertion into NMC bulk which in turn led to a better Li distribution and higher rate capability over pristine NMC. The practical applications of NMC-LLZO are also presented in 2.5 Ah 18650-format lithium-ion batteries. The cells can perform from C/10 to 1C with only 16% capacity reduction and remain 80% retention after cycled up to 500 cycles at a high current density of 1C compared to 40% of NMC cells. Keywords: LiNi0.8Mn0.1Co0.1O2, Lithium-ion batteries, Oxide solid-state electrolyte, Scaffolding layer, High current density

(Digital Presentation) Cobalt Free Cathode Synthesized By Sacrificial Template (α-MnOOH) for Rechargeable Lithium Batteries

LiCoO2 cathode has been used widely for Li-ion batteries (LIBs) for portable applications due to it is compactness, high energy density, excellent cycle life and reliability [1]. Nevertheless, the high cost of cobalt represent some of the limitations of this material [1]. As an alternative, LiNiO2, which iso-structural with LiCoO2, is reported as a stable material for LIB cathodes. Although, the poor thermal stability of this material in operating LIB represents safety risk [2]. On the other hand, LiMnO2 has also been proposed as a low-cost cathode for LIB. However, it is not stable during charging/discharging processes [3]. Ni-rich layer oxide (LiM1-x NxiO2, where M is a transition metal, x > 0.8) appeared as result of much effort dedicated for finding an adequate balance between cost and stability [4]. In comparison to Ni-rich layer, Li-rich layer oxide exhibited better cyclability and safety performance at higher electrode potentials (>4.5 V vs. Li|Li+) [4]. However, the structural and electrochemical properties of the as-prepared materials are determined by the synthesis methods and/or preparation conditions [5]. For instance, the electrochemical performance of Li1.5Ni0.25Mn0.75O2.5 layer material obtained by a simple carbonate coprecipitation method was improved with 240 mAh g-1 and 70.3% of capacity retention after 30 cycles at 0.05C [6].In this work, we report the feasibility of producing a cobalt free cathode LiNi0.5Mn0.5O2 with high energy density using a sacrificial template α -MnOOH as precursor with a simple balance between lithium and nickel content. The synthesis strategies performed in this work led to a promising cathode material with high energy density without sacrificing the operating voltage window, by combining our understanding of the factors governing the cation order with a facile synthetic route that ensured good cation mixing.The LiNi0.5Mn0.5O2 active cathode material was produced by co-precipitated method according to the following procedure: α-MnOOH sacrificial template was synthesized according to ref. [7].Then active cathode material was obtained by co-precipitation method using α-MnOOH, lithium acetate and nickel acetate with a molar ratio of 0.5:1.05:0.5 mol at different treatment temperatures (700°C, 800°C and 900°C). Rate capabilities of all samples are displayed in Fig. 1. The charge-discharge current was increased from 20 mA g-1 (0.1C) to 2000 mA g-1 (10C), and then decreased back to 20 mA g-1. The Li1.05Ni0.5Mn0.5O2 material displayed the best electrochemical performance at 800°C which the initial discharge capacity was 179.9 mAh g-1 . The other samples at 700 °C and 900 °C showed initial discharge capacities of 171.3 mAh g-1 and 156.4 mAh g-1 at 0.1C, respectively. On the other hand, α-MnOOH sacrificial template synthesis showed to be a plausible formation mechanism and the structure–function relationships of LiNi0.5Mn0.5O2.[1] N. Nitta, F. Wu, J. T. Lee, and G. Yushin, “Li-ion battery materials: present and future,” Mater. Today, vol. 18, no. 5, pp. 252–264, Jun. 2015.[2] M. Bianchini, M. Roca-Ayats, P. Hartmann, T. Brezesinski, and J. Janek, “There and Back Again—The Journey of LiNiO2 as a Cathode Active Material,” Angew. Chemie Int. Ed., vol. 58, no. 31, pp. 10434–10458, Jul. 2019.[3] T. Ohzuku and Y. Makimura, “Layered Lithium Insertion Material of LiNi 1/2 Mn 1/2 O 2 : A Possible Alternative to LiCoO 2 for Advanced Lithium-Ion Batteries,” Chem. Lett., vol. 30, no. 8, pp. 744–745, Aug. 2001.[4] G. Hu et al., “A facile cathode design with a LiNi0.6Co0.2Mn0.2O2 core and an AlF3-activated Li1.2Ni0.2Mn0.6O2 shell for Li-ion batteries,” Electrochim. Acta, vol. 265, pp. 391–399, Mar. 2018.[5] C. Zhao, X. Wang, R. Liu, F. Xu, and Q. Shen, “β-MnO2 sacrificial template synthesis of Li 1.2Ni0.13Co0.13Mn0.54O2 for lithium ion battery cathodes,” RSC Adv., vol. 4, no. 14, pp. 7154–7159, Jan. 2014.[6] M. Akhilash, P. S. Salini, K. Jalaja, B. John, and T. D. Mercy, “Synthesis of Li1.5Ni0.25Mn0.75O2.5 cathode material via carbonate co-precipitation method and its electrochemical properties,” Inorg. Chem. Commun., vol. 126, p. 108434, Apr. 2021.[7] F. A. Vásquez, J. E. Thomas, A. Visintin, and J. A. Calderón, “LiMn1.8Ni0.2O4 nanorods obtained from a novel route using α-MnOOH precursor as cathode material for lithium-ion batteries,” Solid State Ionics, vol. 320, pp. 339–346, Jul. 2018. Figure 1

Protective Coating Layers via Phosphazene Compounds for Stabilizing Silicon Anode Materials

In recent years, lithium-ion batteries (LIBs) are widely used in electric vehicles (EVs) and mobile energy storage devices (ESDs), which has led to higher requirements for energy density. To fulfill these requirements, tremendous attention has been paid to design advanced LIBs with various silicon active materials as alternative negative electrodes to replace graphite (372 mAh g-1) due to their high theoretical gravimetric capacity (4200 mA h g-1).[1,2] However, silicon as potential anode material suffers from huge volume changes during charging and discharging and has a poor electronic conductivity which negatively impacts the long-term performance and prevents high silicon contents from practical application.[3] Additionally, an unstable crystalline silicon structure tends to pulverization during the (de)lithiation process.[4] To compensate the volume changes, alleviate pulverization and maintain high electronic conductivity, silicon-doped graphite composites with protecting coating layers are a promising approach. In this context, phosphazene compounds are investigated concerning their silicon protecting properties in silicon-doped graphite composites. In detail electrochemical performance measurements in pouch full-cells (NCM523||SiOx/C), supressing gas formation properties and post-mortem analyzes were carried out to characterize phosphazene compounds as additive materials. The introduction of the dual-additive approach in state-of-the-art electrolytes leads to synergistic effects between FEC and phosphazene compounds which accelerate the durability of silicon particles and results in enhanced electrochemical performance. Reference: [1]Zuo X, Zhu J, Muller‐Buschbaum P, Cheng Y, Silicon based lithium‐ion battery anodes: a chronicle perspective review, Nano Energy, 2017, 31, 113‐143.[2]Jimenez A. R., Klöpsch R., Wagner R., Rodehorst U. C., Kolek M., Nölle R., Winter M., Placke T., A step toward high-energy silicon-based thin film lithium ion batteries, ACS Nano, 2017, 11, 5, 4731-4744.[3] Berla A. L., Lee S. W., Ryu I., Cui Y., Nix W. D., Robustness of amorphous silicon during the initial lithiation/delithiation cycle, Journal of power sources, 2014, 258, 253-259.[4] Casimir A., Zhang H., Ogoke O., Amine J. C., Lu J., Wu G., Silicon-based anodes for lithium-ion batteries: Effectiveness of materials synthesis and electrode preparation, Nano Energy, 2016, 27, 359-376.

Enhanced Safety, High-Rate and High-Voltage Performance of a Lithium-Ion Battery Using Nonflammable Liquid Electrolyte

These days lithium-ion battery (LIB) market is rapidly expanding by electric mobilities and stationary energy storage system industries. One of the biggest challenges in the research and development of advanced LIB is to achieve simultaneously outstanding energy density, cycle life, charge rate, and safety. For fast charging, battery chemistry and reaction kinetics are being evolved from the current hours scale toward minutes scale charging. In the LIB electrolyte perspective, the conventional carbonate-based liquid electrolyte has several limitations in safety and high-rate and high-voltage performance, due to low thermal and anodic stabilities under extreme operation conditions like high temperature, high-current, and high-voltage. To mitigate those issues, we have been developing new and safe electrolyte without any trade-off with cycling performance and energy density of Li-ion batteries. Herein, we present high-rate and high-voltage cycling performance and high safety of nickel-rich cathode-based lithium-ion full-cell fabricated with nonflammable liquid electrolyte. The correlation between the stability of nonflammable liquid electrolyte and its derived solid electrolyte interphase (SEI) and performance will be discussed in this meeting. Acknowledgements This research was supported by the National Research Foundation grant funded by the Ministry of Science and ICT (No. 2019R1A2C1084024).

Battery calendar aging and machine learning

Eric J. Dufek, PhD, is the department manager for the Energy Storage and Electric Transportation Department at Idaho National Laboratory. His research interests span from understanding battery material degradation to electric vehicle infrastructure. Recently he has focused on the use of advanced analysis technigues, including machine learning, to significantly reduce the time needed to make life and failure mode predictions and classifications. By applying these advanced techniques, he hopes to reduce the time needed to transition high-energy and fast-charge battery technologies from the benchtop to consumer adoption. Tanvir R. Tanim, PhD, is an R&D engineer and the group lead for the Energy Storage Technology Group in the Energy Storage and Electric Transportation Department at Idaho National Laboratory. His research focuses on enabling next-generation high-energy and power lithium-ion batteries, developing advanced algorithms for reliable life estimation, and expanding and/or verifying advanced diagnostics and prognostics of these high-energy and power batteries for electric vehicle applications. Between 2011 and 2022, he authored or co-authored 38 peer-reviewed scientific articles and patents. Bor-Rong Chen, PhD, is a staff scientist at Idaho National Laboratory (INL) in the Energy Storage and Electric Transportation Department. She earned a PhD in materials science and engineering from Northwestern University in the US. Her research interest is the early identification of degradation mechanisms in Li-ion batteries and the development of advanced materials for high-energy batteries. Sangwook Kim, PhD, is a staff engineer in the Energy Storage and Electric Transportation Department at Idaho National Laboratory (INL). He obtained his MS and PhD from the Department of Mechanical Engineering at North Carolina State University in 2015 and 2019. During his PhD program, he was awarded a 2018 INL Graduate Fellowship. His current research focuses on understanding aging modes and the development of diagnostic/prognostics tools for advanced lithium-ion and lithium metal batteries. Eric J. Dufek, PhD, is the department manager for the Energy Storage and Electric Transportation Department at Idaho National Laboratory. His research interests span from understanding battery material degradation to electric vehicle infrastructure. Recently he has focused on the use of advanced analysis technigues, including machine learning, to significantly reduce the time needed to make life and failure mode predictions and classifications. By applying these advanced techniques, he hopes to reduce the time needed to transition high-energy and fast-charge battery technologies from the benchtop to consumer adoption. Tanvir R. Tanim, PhD, is an R&D engineer and the group lead for the Energy Storage Technology Group in the Energy Storage and Electric Transportation Department at Idaho National Laboratory. His research focuses on enabling next-generation high-energy and power lithium-ion batteries, developing advanced algorithms for reliable life estimation, and expanding and/or verifying advanced diagnostics and prognostics of these high-energy and power batteries for electric vehicle applications. Between 2011 and 2022, he authored or co-authored 38 peer-reviewed scientific articles and patents. Bor-Rong Chen, PhD, is a staff scientist at Idaho National Laboratory (INL) in the Energy Storage and Electric Transportation Department. She earned a PhD in materials science and engineering from Northwestern University in the US. Her research interest is the early identification of degradation mechanisms in Li-ion batteries and the development of advanced materials for high-energy batteries. Sangwook Kim, PhD, is a staff engineer in the Energy Storage and Electric Transportation Department at Idaho National Laboratory (INL). He obtained his MS and PhD from the Department of Mechanical Engineering at North Carolina State University in 2015 and 2019. During his PhD program, he was awarded a 2018 INL Graduate Fellowship. His current research focuses on understanding aging modes and the development of diagnostic/prognostics tools for advanced lithium-ion and lithium metal batteries.

Dual-stable engineering enables high-performance Zn2SnO4-based lithium-ion battery anode

The promising high-capacity anode material of Zn2SnO4 suffers from large volume expansion and poor conductivity during cycle, and hence its practical application in lithium-ion batteries is blocked seriously. Herein, to achieve high capacity and improved cyclic stability of Zn2SnO4-based anode, we introduce a dual-stable engineering strategy that the Zn2SnO4 is encapsulated within a porous carbon shell and a void structure is constructed between the inner Zn2SnO4 and outer carbon shell simultaneously. The as-fabricated Zn2SnO4-based composite is therefore referred to as Zn2SnO4 @[email protected] It is demonstrated that the combined action of the porous carbon and the void effectively suppresses the volume effect of the Zn2SnO4 and enhances the electrochemical kinetics of the electrodes and hence the structural stability and electrochemical kinetics of the Zn2SnO4 @[email protected] are improved significantly. As a result, the Zn2SnO4 @[email protected] delivers 961.5 mA h g−1 after 350 cycles at 200 mA g−1 and 438.2 mA h g−1 after 600 cycles at 1000 mA g−1, thereby having potential application in advanced lithium-ion battery anodes.