Generation Lithium-ion Batteries Research Articles

High Throughput Experimental Technologies for Li-Ion Batteries

Next generation Lithium ion batteries materials with higher energy, lower cost, long lifetime, and better safety, require the investigation of unknown lithium-ion systems and a vast amount of experiments. Advanced cathode, anode and electrolyte materials discovery is one possible solution to the rapid optimization. In this work, MTI Corporation and MTI SZKJ’s effort on modify the existing technologies to develop a high throughput materials experimental line for Lithium-ion batteries materials research are reviewed and discussed.The first step is high throughput, automatic dispensing of solid powders or liquid. Five powder or six liquid dispensing heads and balances, with one dispensing head for each material component, are integrated with a carousel type sample changer for automatic powder or liquid dispensing with varying ratios between different material components. The second step is high throughput ball milling of the as-dispensed powder samples. With 4 sets of 4 cavity milling jars, totally 16 parallel ball milling experiments of 10 g samples can be carried out in a planetary ball mill machine. The mixed powder samples are then high throughput pellet pressed by a 10 ton electric hydraulic press with a carrousel type sample changer. Next, a compact 16-channel tube furnace up to 1100 °C is employed for sintering, annealing, or quenching operations. Finally, the elemental compositions of bulk samples are high throughput analyzed by an X-ray fluorescence (XRF) scanning system for providing instant feedbacks to the synthesis / processing steps. Keywords: Li-ion Batteries Materials Discovery, High Throughput Figure 1

Magnetic Resonance Imaging and Molecular Dynamics Characterization of Ionic Liquid in Poly(ethylene oxide)-Based Polymer Electrolytes.

Ternary systems consisting of polymers, lithium salts, and ionic liquids (ILs) are promising materials for the development of next-generation lithium batteries. The ternary systems combine the advantages of polymer–salt and IL–salt systems, thus providing media with high ionic conductivity and solid-like mechanical properties. In this work, we apply nuclear magnetic resonance 1H microimaging [magnetic resonance imaging (MRI)] techniques and molecular dynamics (MD) simulations to study the translational and rotational dynamics of the N-butyl-N-methylpyrrolidinium (PYR14) cation in poly(ethylene oxide) (PEO) matrices containing the lithium bis(trifluoromethanesulfonyl) imide salt (LiTFSI) and the PYR14TFSI IL. The analysis of diffusion-weighted images in PEO/LiTFSI/PYR14TFSI samples with varying mole ratios (10:1:x, with x = 1, 2, 3, and 4) shows, in a wide range of temperatures, a spatially heterogeneous distribution of PYR14 diffusion coefficients. Their weight-averaged values increase with IL content but remain well below the values estimated for the neat IL. The analysis of T2 (spin–spin relaxation) parametric images shows that the PEO matrix significantly hinders PYR14 rotational freedom, which is only partially restored by increasing the IL content. The MD simulations, performed on IL-filled cavities within the PEO matrix, reveal that PYR14 diffusion is mainly affected by Li/TFSI coordination within the IL phase. In agreement with MRI experiments, increasing the IL content increases the PYR14 diffusion coefficients. Finally, the analysis of MD trajectories suggests that Li diffusion mostly develops within the IL phase, although a fraction of Li cations is strongly coordinated by PEO oxygen atoms.

Scalable synthesis of nanoporous silicon microparticles for highly cyclable lithium-ion batteries

Nanoporous silicon is a promising anode material for high energy density batteries due to its high cycling stability and high tap density compared to other nanostructured anode materials. However, the high cost of synthesis and low yield of nanoporous silicon limit its practical application. Here, we develop a scalable, low-cost top-down process of controlled oxidation of Mg2Si in the air, followed by HCl removal of MgO to generate nanoporous silicon without the use of HF. By controlling the synthesis conditions, the oxygen content, grain size and yield of the porous silicon are simultaneously optimized from commercial standpoints. In situ environmental transmission electron microscopy reveals the reaction mechanism; the Mg2Si microparticle reacts with O2 to form MgO and Si, while preventing SiO2 formation. Owing to the low oxygen content and microscale secondary structure, the nanoporous silicon delivers a higher initial reversible capacity and initial Coulombic efficiency compared to commercial Si nanoparticles (3,033 mAh/g vs. 2,418 mAh/g, 84.3% vs. 73.1%). Synthesis is highly scalable, and a yield of 90.4% is achieved for the porous Si nanostructure with the capability to make an excess of 10 g per batch. Our synthetic nanoporous silicon is promising for practical applications in next generation lithium-ion batteries.

Electron Microscopy Investigation of Rice Husk-Derived Silicon-Tin/Nitrogen-Doped Graphene Composites Nanostructure

Nowadays, there is an increasing of the demanding in high energy density lithium-ion batteries (LIBs) due to the growing of energy storage needs for electronic vehicles and portable devices. Silicon (Si) and Tin (Sn) are the promising anode materials for LIBs due to their high theoretical capacity of 4200 mAh/g and 994 mAh/g. Moreover, Si can be derived from rice husk which is the main agricultural product in Thailand. However, the using of Si and Sn encounters with the huge volume expansion during lithiation and delithiation process. To alleviate this problem, Nitrogen-doped graphene (NrGO), carbon supporter, is used as composite with these metals to buffer the volume change and increase the electrical conductivity of composites. This work aims to synthesis Si/NrGO and SiSn/NrGO nanocomposites and Si used in these composites is derived from rice husk. All products were characterized by X-rays diffraction (XRD), Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. XRD results showed that the composites contained phases of Si, Sn and carbon. The electron microscopy techniques were the main part to clarify the morphology and distribution of Si and Sn particles on NrGO. SEM and TEM results confirm that there were small sized particles of Si and Sn dispersed and covered on NrGO surface. Furthermore, the electrochemical properties of prepared composites were measured to confirm their efficiency as anode materials in lithium-ion batteries by coin cell assembly. The composite with 10 percent Si and 10 percent Sn on NrGO could deliver a high capacity around 480 mAh/g over 100 cycles and expected to use as anode materials in the next generation lithium-ion batteries.

Facilely tunable core-shell Si@SiOx nanostructures prepared in aqueous solution for lithium ion battery anode

Silicon with higher theoretical capacity than that of the commercial graphite anode is considered as the next generation lithium ion battery anode materials. Herein, our research demonstrates that the surface SiOx coating with silanol groups generated in aqueous solution on silicon nanoparticles can efficiently improve their electrochemical performance. The SiOx layer can suppress the volume expansion of silicon particles, and the surficial silanol groups can also contribute to the enhanced electrochemical performance. Both coulombic efficiency and cycling stability can be improved with the optimal SiOx coating thickness. This work provides a facile avenue of surface engineering of silicon nanoparticle for the high-performance lithium ion battery Si anode.

Target encapsulating NiMoO4 nanocrystals into 1D carbon nanofibers as free-standing anode material for lithium-ion batteries with enhanced cycle performance

Recently, NiMoO4 has attracted much interest because of its high theoretical capacity and redox activity as lithium-ion batteries (LIBs). However, its applications are limited by its poor cycling stability and rate performance. In this paper, NiMoO4 nanofibers (NiMoO4-NFs) were fabricated via scalable electrospinning technique. The prepared NiMoO4-NFs were directly used as electrode materials without any current collector. Electrochemical tests demonstrated that the NiMoO4-NFs exhibited desired electrochemical performance including high reversible capacity (892.7 mA h g−1), superior long-term cycle stability and rate capacity (511 mA h g−1 at 1 A g−1 after 500 cycles). The electrochemical reaction mechanism was explored by using ex situ transmission electron microscopy. A two-phase reaction process was confirmed in the electrochemical reaction. The desired electrochemical properties made NiMoO4-NFs appropriate for the next generation of LIBs.

MoS2 Nanoflower-Derived Interconnected CoMoO4 Nanoarchitectures as a Stable and High Rate Performing Anode for Lithium-Ion Battery Applications.

In recent years, conversion-based mixed transition-metal oxides have emerged as a potential anode for the next generation lithium-ion batteries because of their high theoretical capacity and high rate performance. Herein, an interconnected cobalt molybdenum oxide (CoMoO4) nanoarchitecture derived from molybdenum sulfide (MoS2) nanoflowers is investigated as an anode for lithium-ion batteries. The interconnected CoMoO4 displayed an excellent discharge capacity of 1100 mA h g-1 over 100 cycles at a current rate of C/5. Moreover, the material exhibited an enhanced electrochemical stability, high rate performance, and delivered high discharge capacities of 600 and 220 mA h g-1, respectively, at 5 C and 10 C after 500 cycles. The excellent cycling stability and high rate performance of interconnected CoMoO4 are credited to its unique architecture and porous morphology. The above characteristics and the synergetic effect between the constituting metal ions not only provided a shorter diffusion path for the lithium-ion conduction but also improved the electronic conductivity and mechanical strength of the anode. The field-emission scanning electron microscopy analysis of the electrochemically cycled electrode revealed good structural integrity of the electrode. Further, the practical feasibility of interconnected CoMoO4 in the full cell was analyzed by integrating it with the LiNi0.8Mn0.1Co0.1O2 cathode, which demonstrated excellent cycling stability and high rate performance.

Rice husk lignin-based porous carbon and ZnO composite as an anode for high-performance lithium-ion batteries

ZnO is considered to be the next generation lithium-ion battery anode material due to its high theoretical capacity, low potential, abundant resources and low toxicity. However, high volume expansion during charge–discharge process makes ZnO powdered and agglomerated easily. In the work, we fabricate a porous carbon skeleton by using rice husk (RH) lignin, and the ZnO nanoparticles are supported on the skeleton uniformly. Its unique structure provides excellent stability and electrical conductivity. RH as a carbon source will improve the utilization rate of biomass materials in the refining process. The samples were characterised by XRD, Raman, TG, SEM and transmission electron microscopy, and the materials presented a promising Li storage properties and electrochemical performance with a discharge capacity of 898.1 mAh g−1 at 0.2C after 110 cycles, which is very close to the theoretical specific capacity of zinc oxide (978 mAh g−1).

Preparation and Electrochemical Performance of CoSe2−MnSe2 for Application in Lithium‐Ion Batteries

AbstractIn recent years, lithium‐ion batteries (LIBs) have been widely used in many fields, and research on LIBs electrode materials have attracted much attention. Among them, transition metal selenides (TMSs) are the most promising candidates in the next generation LIBs due to their high theoretical specific capacity and electrical conductivity. However, poor cycle stability and severe volume variation result in serious capacity decay during the charge/discharge process, limiting the practical application. In this paper, CoSe2−MnSe2 composites are synthesized via Co−Mn‐based metal‐organic framework (MOF) precursor. Meanwhile, three types of materials are successfully synthesized including CoSe2‐MnSe2@reduced graphene oxide (rGO), CoSe2‐MnSe2@polypyrrole (PPy), and CoSe2‐MnSe2/glucose (C). According to the electrochemical test results, it can be seen that the electrochemical performance of CoSe2−MnSe2 has been improved significantly. CoSe2‐MnSe2@rGO electrode materials, in particular, of which the inactivation defect sites and special carbon structure of rGO could provide more attachment points for ions. Due to the perfect combination of rGO and CoSe2−MnSe2, the CoSe2‐MnSe2@rGO composites display outstanding rate performance (1266 mA h g−1 at current densities of 100 mA g−1) and high reversible capacity (1169 after 150 cycles at 100 mA g−1). We believe that CoSe2‐MnSe2@rGO is a kind of very promising anode material.

An ion-conductive Li7La3Zr2O12-based composite membrane for dendrite-free lithium metal batteries

Lithium (Li) metal is pursued as the anode for next generation lithium batteries because of the highest energy density and the lowest reduction potential. However, the formation of lithium dendrite caused by nonuniform Li deposition exists. Moreover, the safety issue arising from hazardous Li dendrites hinders the practical application of lithium metal batteries (LMBs). In this work, an organic and inorganic composite protective membrane (CPM) consisting of PVDF-HFP and LLZO particles is prepared by a simple tape-casting method. The CPM modified Li symmetric cell exhibits no obvious voltage hysteresis over 500 h at 2 mA cm−2 and 1 mAh cm−2. Moreover, the CPM modified Li | LFP cell can stably run 800 cycles at 1C and retain a high average Coulombic efficiency of ~99.95%. Moreover, the in-situ formation of LiF between metallic Li anode and the C–F group in PVDF-HFP exhibits high modulus, effectively suppressing the growth of lithium dendrites. The uniform Li deposition is achieved owing to the high ionic conductivity and Li+ transference number of CPM. In addition, the high modulus LiF layer can stabilize interface and greatly reduce interfacial resistance after cycling.

Synthesis of graphene-siloxene nanosheet based layered composite materials by tuning its interface chemistry: An efficient anode with overwhelming electrochemical performances for lithium-ion batteries

Owing to its high theoretical storage capacity, two dimensional (2D) silicon nanosheets is the one among the most exciting anode material for the next generation lithium ion (Li-ion) batteries. However, deprived electrochemical properties due to the huge volume expansion resulting in rapid capacity decay, thereby hindering its commercial application aspect of silicon nanosheet based materials. The present work proposes a novel concept of synthesizing graphene-siloxene (SiG) based multi-layered structures by tuning the interface chemistries of graphene oxide and siloxene sheets derived from topochemical transformation of calcium silicide (CaSi2). Morphological characterization using Field emission scanning electron microscopic and transmission electron microscopy reveal the successful formation of few- to multi-layered SiG composite materials with intercalated/surface grafted siloxene nanosheets on the graphene layers. Owing to its hierarchical composite structure, SiG as anode delivers the first discharge and charge capacity values as high as 3880 mAhg−1 and 3016 mAhg−1 respectively measured at the current rate of 205 mAg−1. Even at high current rate (4.1 Ag-1), SiG composite materials delivers first charge capacity of 1480 mAhg−1 with good cycling performance (1040 mAhg−1) after 1000 cycles. Due to its enhanced lithium storage, cycling stability and rate capability, synthesized SiG composites could be a potential anode candidate for Li-ion batteries.

A 2D covalent organic framework as a high-performance cathode material for lithium-ion batteries

Organic cathode materials for lithium storage have attracted wide attention owing to their very diverse structures and largely tuned engineered molecular levels. However, it remains a great challenge to design a cathode material with simultaneously combined features of high specific capacity, cycle life and rate performance. Here, based on our proposed strategy, we design and report a BQ1-COF consisting of maximum active groups (C=O and C=N) with minimal inactive groups, which when used as cathode materials for lithium-ion batteries give a reversible capacity of 502.4 mA h g−1 at 0.05C, so far the highest capacity among polymer-based cathode materials. More importantly, the stable framework structure delivers an excellent capacity retention (81% after 1,000 cycles at 1.54 A g−1), and it is noted that the rate performance (170.7 mA h g−1 even at 7.73 A g−1) is far superior to previous related reports. These results indicate that maximizing the loading of redox active groups in a stable network structure is an effective strategy to design organic cathode materials simultaneously with high capacity and outstanding cycle and rate performance for next generation lithium-ion batteries.

From Intercalation to Alloying Chemistry: Structural Design of Silicon Anodes for the Next Generation of Lithium-ion Batteries

From Intercalation to Alloying Chemistry: Structural Design of Silicon Anodes for the Next Generation of Lithium-ion Batteries

A Nanosilver Embedded Graphite-C Shell Coating on Large Size Micro Silicon Formed by Low Temperature Carbonizing with Ag+ Increased the Cross-Linking of Alginate as an Anode for LIBs

Silicon (Si) is an aussichtsreich anode candidate for a new generation lithium-ion batteries on account of its enormous theoretical capacity. However, its progress is tremendously hindered due to the tremendous volumetric change causes structure instability and poor cycling stability during the charge/discharge cycle. To overcome these issues associated with Si anodes, fabricated Si/C composites have been extensively studied. Here, this paper exploits a method for preparing a Si/C composite at low temperature and under atmospheric conditions, which has a graphite-C layer embedded with nanosilver particles. Carboxyl-rich alginate as a carbon source which silicon-carbon was tightly bound due to forms strong bonds (hydrogen bond) on the silicon surface. Tiny silver ions (0.01 M) were added to improve carbon stability by enhancing the cross-linking of alginate coated on the surface of large size micro silicon powder. The Si/Ag@C ternary composites were obtained, which combined simultaneous synthesis of nanosilver and crack-free graphite-C by subsequent low-temperature carbonization at 480 °C. Si/Ag@C exhibits high conductivity and long period recycle stability due to inducing high conductivity of nanosilver and crack-free graphite-C as anodes for LIBs. Si/Ag@C shows a well reversible capacity (724 mAh/g) over 100 cycles at 200 mA/g, which is more than thirty times that of Si (21 mAh/g). Si/Ag@C shows low electrochemical impedance and satisfactory rate capability due to its special structure.

Facile synthesis of CTAB assisted hierarchical-structure TiO2@SnO2 for lithium storage

Tin oxide (SnO2) with high specific capacity and excellent safety performance has become potential candidate for next generation lithium-ion batteries (LIBs). However, the practical application of SnO2 is hindered by large volume change and particle aggregation. Herein, a type of three-dimensional (3D) hierarchical porous titanium-based microclews composed of one-dimensional (1D) titanium dioxide (TiO2) nanoribbons and SnO2 nanoparicles, is synthesized for the first time with the assistance of cationic surfactant, cetyltrimethylammonium bromidewere (CTAB). SnO2 nanoparticles distribute uniformly on the nanoribbons, and CTAB as growth controller plays a key role in the formation of the uniform and stable hierarchical-structure. The as-synthesized CTAB assisted hierarchical-structure TiO2@SnO2 microclews (CA–TiO2@SnO2 MCs) elelctrode demonstrates outstanding ionic conductivity due to the structure assisting efficient contact between electrode and electrolyte, with a remarkable discharge capacity of 448.3 mAh g−1 after cycling for 500 times at a current density of 500 mA g−1, and a capacity retention of 558.8 mAh g−1 at 200 mA g−1 after 400 cycles in LIBs.

Features of improved capacity at high discharge rate of K-doped Li-rich cathodes for LIBs

Li-rich oxides are one of the most promising cathode materials for the new generation of lithium-ion batteries (LIBs). This work describes the preparations of Li-rich cathode materials with composition Li1.20Ni0.13Co0.13Mn0.54O2 and the potassium – doped material Li1.15K0.05Ni0.13Co0.13Mn0.54O2. The oxides are synthesized from acetates of metals by sol-gel synthesis followed by high-temperature annealing. All materials are characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) with elemental analysis by EDX and elemental mapping. We also measure granulometric compositions of the powders by laser particle size analyzer. The samples were tested as cathode material in half-cells with lithium metal as the anode. The results of these electrochemical tests are presented in the article. Potassium – doped Li-rich oxides show more than 260 mAh/g discharge capacity, at current rate 0.1C and higher discharge capacity after increasing discharge current.

Effect of Mn, Ni, Co transition metal ratios in lithium rich metal oxide cathodes on lithium ion battery performance

Lithium rich layered metal oxide is a high energy density cathode material for new generation lithium-ion batteries (LIBs). This material has Li [Li1/3Mn2/3]O2 and LiMO2 (M: Ni, Co, Mn, Al etc.) structure and exhibit higher irreversible capacity and cycle life than conventional cathode materials. In this study, the stoichiometry of metals in the lithium rich cathode material formulation was investigated by changing Mn, Ni and Co ratios. Li1.2Mn0.49+xCo0.2-2xNi0.2-2xAl0.02O2 (x = 0, 0.01, 0.02, 0.03). formulation was used and the prepared lithium rich cathode active powders were structurally characterized by XRD, ICP and NAA. Li-rich cathodes were tested by electrochemical methods, too.

Atomic Force Microscopy Applications to the Next Generation Lithium-ion Batteries

Atomic Force Microscopy Applications to the Next Generation Lithium-ion Batteries

Novel S-doped ordered mesoporous carbon nanospheres toward advanced lithium metal anodes

Lithium metal anode has been considered as an ideal anode for the next generation lithium batteries owing to its high energy density. However, its practical application is still limited by the low Coulombic efficiency and poor safety performance due to the lithium dendrites caused by uncontrollable lithium deposition and unstable solid electrolyte interphase. In this work, we report for the first time the in-situ synthesis of S-doped carbon nanospheres with ordered mesoporous channels used as the functional scaffold for safe and stable lithium metal anode. S-doping, large surface area and ordered mesoporous structure of the carbon spheres provide homogenous nucleation sites, regulated local current density and facilitated mass transport, which induce uniform lithium nucleation and the subsequent dendrite-free growth. As a result, the fabricated anode exhibits high Coulombic efficiency up to ~97.5% within 220 cycles. The symmetric cell also presents stable potential hysteresis below 15 mV with ultralong cycling life up to 1600 h at a current density of 0.5 mA cm-2. Full cell coupled with commercial LiFePO4 as cathode delivers a high reversible capacity of ~135.0 mAh g-1 after 300 cycles at 1 C, showing high potential in practical application as stable lithium metal anodes.

Nanoscale characterization of solid electrolyte by Scanning Probe Microscopy techniques

All-solid-state battery is potentially for the next generation lithium ion battery. In all-solid-state battery, the solid electrolyte plays the most important role. However, the nanoscale electrochemical properties of the solid electrolyte are not well understood yet. In this study, by using Scanning Probe Microscopy (SPM) based techniques, including Atomic Force Microscopy (AFM) and Electrochemical Strain Microscopy (ESM), the electrochemical deformation within grains and grain boundaries in the NASICON-structured (sodium (Na) Super Ionic CONductor) Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid electrolyte is studied at the nanoscale first time. The different electrochemical responses at grains and grain boundaries of the LAGP solid electrolyte are observed clearly due to different lithium ion conductivities insides the grains and along the grain boundaries. These results provide the new insights on the nanoscale electrochemical mechanisms and development of the solid electrolyte materials.