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Compared with conventional liquid electrolytes, solid electrolytes can better improve the safety properties and achieve high-energy-density Li-ion batteries. Sulfide-based solid electrolytes have attracted significant attention owing to their high ionic conductivities, which are comparable to those of their liquid counterparts. Among them, Li thiophosphates, including Li-argyrodites, are widely studied. In this study, Li thiophosphate solid electrolytes containing BH

In this study, we present improved power characteristics and suppressed phase transition by incorporating elemental doping into a P2-type cathode of sodium ion batteries. A Cu-doped Fe–Mn based P2-type Na0.67Cu0.125Fe0.375Mn0.5O2 cathode was designed based on the calculations of the electronic structure and then examined experimentally. Using first principles, we introduced instrinsic p-type conductivity by elemental doping with Cu. Introduction of Cu generated electron holes above the Fermi level in the electronic structure, which is typical of p-type semiconductors. Charge analyses suggested that the hole generation was driven primarily by the greater reduced characteristics of Cu as compared with those of Fe and Mn. In addition, introduction of Cu retaining high reduced property also suppressed phase transition from the P2 to Z phase by Fe migration to empty Na layers mainly. Electrochemical experiments revealed improved power characteristics upon the introduction of p-type conductivity. This could be attributed to the increase in the electronic conductivity by hole generation in the valence band. This study suggests that the introduction of p-type conductivity could be a rational tactic for the development of promising cathode materials for high performance sodium ion batteries.

All-solid-state batteries (ASSBs) with inorganic solid electrolytes (SEs) have received much attention as future energy storage systems owing to their high energy densities and excellent safety. Sulfide-based SEs are considered promising because they exhibit greater ionic conductivities and mechanical softness than oxide-based SEs. In particular, argyrodite-type Li6PS5Cl with a high ionic conductivity of 3.0 × 10−3 S cm−1 offers new possibilities for realizing high-performance ASSBs. However, contact with moisture results in the evolution of H2S from Li6PS5Cl, which has hindered the scalable fabrication and practical application of Li6PS5Cl. To avoid this issue, we propose incorporating a zeolite, which can act as a scavenger for both toxic H2S gas and moisture, as a functional additive in Li6PS5Cl. We demonstrate that zeolite-embedded Li6PS5Cl exhibits greatly improved chemical stability and reduced H2S evolution upon storage in humid air (RH 50%), leading to a noticeable improvement in the cycle performance of ASSBs. This approach could resolve the technical issues associated with sulfide-based SEs toward commercial-scale implementation.

In the development of a reliable cathode material for lithium-ion batteries (LIBs), it is crucial to clearly understand the structural degradation mechanism and its correlation with the electrochem...

The wet-chemical processability of sulfide solid electrolytes (SEs) provides intriguing opportunities for all-solid-state batteries. Thus far, sulfide SEs are wet-prepared either from solid precursors suspended in solvents (suspension synthesis) or from homogeneous solutions using SEs (solution process) with restricted composition spaces. Here, a universal solution synthesis method for preparing sulfide SEs from precursors, not only Li

GPD encodes glyceraldehyde-3-phosphate dehydrogenase enzyme involved in sugar mobilization, particularly glycolysis and gluconeogenesis. The objective of this study was to determine physiological aspects of germination and early seedling establishment of PsGPD (Pleurotus sajor-caju glyceraldehyde-3-phosphate dehydrogenase) expressing transgenic rice (T5) against different salt concentrations. The T5 line that carried 2 copies of T-DNA and had the highest level of PsGPD expression was used in the investigation. Final germination percentage, amylase activity, reducing sugar accumulation, and chlorophyll biosynthesis were comparatively higher in PsGPD expressing transgenic rice against elevating saline conditions. A slow-paced conversion of porphyrin's precursors was seen through the matrix model and further elaborated by a graphical model. A sustained level of porphyrin was observed in PsGPD expressing transgenic rice. These data were concurrent with the relative gene expression and thermal imaging (thermography) of PsGPD expressing transgenic rice against salt stress. Morphological attributes also favored the salt tolerance exhibited by PsGPD-transformed rice., Graphical Abstract

All-solid-state lithium-ion batteries (ASLBs) employing sulfide solid electrolytes are attractive next-generation rechargeable batteries that could offer improved safety and energy density. Recently, wet syntheses or processes for sulfide solid electrolyte materials have opened opportunities to explore new materials and practical fabrication methods for ASLBs. A new wet-chemical route for the synthesis of Li-deficient Li3-x PS4 (0≤x≤0.3) has been developed, which is enabled by dual solvents. Owing to its miscibility with tetrahydrofuran and ability to dissolve elemental sulfur, o-xylene as a cosolvent facilitates the wet-chemical synthesis of Li3-x PS4 . Li3-x PS4 (0≤x≤0.15) derived by using dual solvents shows Li+ conductivity of approximately 0.2 mS cm-1 at 30 °C, in contrast to 0.034 mS cm-1 for a sample obtained by using a conventional single solvent (tetrahydrofuran, x=0.15). The evolution of the structure for Li3-x PS4 is also investigated by complementary analysis using X-ray diffraction, Raman, and X-ray photoelectron spectroscopy measurements. LiCoO2 /Li-In ASLBs employing Li2.85 PS4 obtained by using dual solvents exhibit a reversible capacity of 130 mA h g-1 with good cycle retention at 30 °C, outperforming cells with Li2.85 PS4 obtained by using a conventional single solvent.

Silicon oxide-based materials for Li-ion battery anodes have attracted extensive attention due to their higher capacity than graphite materials and better cycling performance compared to Si-based materials. However, the cycle performance needs to be further enhanced if they are to be widely used in commercial applications. In this study, we propose a simple strategy to prepare porous SiOx materials. Zn and SiO were combined by a high-energy mechanical milling process. The Zn/SiO composite was then heated to 900 °C and the Zn-based materials were removed by evaporation as Zn is a metal with a relatively low melting point (419.5 °C) and boiling point (907 °C). This process resulted in the production of porous SiOx materials with a large number of mesopores. Characterizations of the materials by X-ray diffraction analysis, X-ray photoelectron spectroscopy, and electron microscopy confirmed the synthesis of porous SiOx materials. The cycling performance of these materials was found to be improved. Carbon incorporation was performed in an effort to further enhance their performance, and the cycling performance of these porous SiOx/C composite materials was considerably enhanced, thus indicating that the strategy involving both a porous structure and carbon incorporation is very effective for improvement of the cycling stability of Li-alloy-based active materials.

In plants, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a main enzyme in the glycolytic pathway. It plays an essential role in glycerolipid metabolism and response to various stresses. To examine the function of PsGAPDH (Pleurotus sajor-caju GAPDH) in response to abiotic stress, we generated transgenic rice plants with single-copy/intergenic/homozygous overexpression PsGAPDH (PsGAPDH-OX) and investigated their responses to salinity stress. Seedling growth and germination rates of PsGAPDH-OX were significantly increased under salt stress conditions compared to those of the wild type. To elucidate the role of PsGAPDH-OX in salt stress tolerance of rice, an Illumina HiSeq 2000 platform was used to analyze transcriptome profiles of leaves under salt stress. Analysis results of sequencing data showed that 1124 transcripts were differentially expressed. Using the list of differentially expressed genes (DEGs), functional enrichment analyses of DEGs such as Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were performed. KEGG pathway enrichment analysis revealed that unigenes exhibiting differential expression were involved in starch and sucrose metabolism. Interestingly, trehalose-6-phosphate synthase (TPS) genes, of which expression was enhanced by abiotic stress, showed a significant difference in PsGAPDH-OX. Findings of this study suggest that PsGAPDH plays a role in the adaptation of rice plants to salt stress.

In this study, we present improved power characteristics and suppressed phase transition by incorporating elemental doping into a P2-type cathode of sodium ion batteries. A Cu-doped Fe-Mn based P2-type Na0.67Cu0.125Fe0.375Mn0.5O2 cathode was designed based on the calculations of the electronic structure and then examined experimentally. Using first principles, we introduced instrinsic p-type conductivity by elemental doping with Cu. Introduction of Cu generated electron holes above the Fermi level in the electronic structure, which is typical of p-type semiconductors. Charge analyses suggested that the hole generation was driven primarily by the greater reduced characteristics of Cu as compared with those of Fe and Mn. In addition, introduction of Cu retaining high reduced property also suppressed phase transition from the P2 to Z phase by Fe migration to empty Na layers mainly. Electrochemical experiments revealed improved power characteristics upon the introduction of p-type conductivity. This could be attributed to the increase in the electronic conductivity by hole generation in the valence band. This study suggests that the introduction of p-type conductivity could be a rational tactic for the development of promising cathode materials for high performance sodium ion batteries.

Sulfide‐based all‐solid‐state batteries (ASSBs) have been featured as promising alternatives to the current lithium‐ion batteries (LIBs) mainly owing to their superior safety. Nevertheless, a solution‐based scalable manufacturing scheme has not yet been established because of the incompatible polarity of the binder, solvent, and sulfide electrolyte during slurry preparation. This dilemma is overcome by subjecting the acrylate (co)polymeric binders to protection−deprotection chemistry. Protection by the tert‐butyl group allows for homogeneous dispersion of the binder in the slurry based on a relatively less polar solvent, with subsequent heat‐treatment during the drying process to cleave the tert‐butyl group. This exposes the polar carboxylic acid groups, which are then able to engage in hydrogen bonding with the active cathode material, high‐nickel layered oxide. Deprotection strengthens the electrode adhesion such that the strength equals that of commercial LIB electrodes, and the key electrochemical performance parameters are improved markedly in both half‐cell and full‐cell settings. The present study highlights the potential of sulfide‐based ASSBs for scalable manufacturing and also provides insights that protection−deprotection chemistry can generally be used for various battery cells that suffer from polarity incompatibility among multiple electrode components.

Titanium doping on LiNi1/3Co1/3Mn1/3O2 cathode material is performed in a bid to improve its electrochemical and thermal properties at high voltage. The particle hardness is measured in order to verify the structural stability, and is found to improve from 104 to 143 MPa as a result of the Ti doping. Thus, high electrode density is obtained with less cracked particles in the electrode. Electrode density of 3.9 g cm−3 is employed in order to confirm the effect of particle hardness on the electrochemical performance. The cycle performance is evaluated at 4.5 V and high temperature of 60 °C, and the obtained capacity retention after 50 cycles is found to be significantly improved via Ti doping. The cycled electrodes show that the generation of crack inside particles are suppressed for Ti-doped LiNi1/3Co1/3Mn1/3O2. The thermal stability of the charged electrode is also improved via Ti doping, because of the enhanced structural stability. On the basis of these results, Ti is considered to be a viable dopant for improving particle hardness, which is an important factor as regards improving the electrochemical and thermal properties of LiNi1/3Co1/3Mn1/3O2.

Titanium doping is employed to enhance the structural strength of a high-Ni layered cathode material in lithium ion batteries during high temperature cycling. After Ti-doping, the external morphology remains similar, but the lattice parameters of the layered structure are slightly shifted toward larger values. With application of the prepared materials as cathodes in lithium-ion batteries, the initial capacities are similar but the cycling performance at 25 °C is enhanced by Ti-doping. During high temperature cycling at 60 °C, furthermore, highly improved capacity retention is achieved with the Ti-doped material (95% of initial capacity at 50th cycles), while cycle fading is accelerated with the bare electrode. This enhancement is attributed to better retention of the compressive strength of the particles and retarded crack formation within the particles. In addition, impedance increase is reduced in the Ti-doped electrode, which is attributed to an improvement in the structural strength of the high-Ni cathode material with Ti-doping.

A facile Mn surface doping process is proposed to improve the thermal and structural stabilities of Ni-rich layered cathode materials (Ni ≥ 80%) for lithium-ion batteries in electric vehicles. Herein, we demonstrate that the surface structure of the Ni-rich layered cathode materials can be stabilized by the introduction of a thin Mn-rich surface layer. This layer effectively reduces the direct exposure of the highly reactive Ni on the surface of the cathode materials, thus enhancing thermal stability and mitigating side reactions associated with highly reactive Ni that causes the loss of reversible capacity. In practice, the Mn surface-doped Ni-rich layered cathode material exhibits a high specific capacity with an improved cycling stability even at a high temperature (60 °C). We believe that our simple approach offers more opportunities to upscale production without any extra caution.

Improving cycle performance and rate-capability of lithium ion batteries is necessary in moving toward their use in electric vehicles. Working towards this goal, we propose an amorphous Li-Zr-O coating on the surface of a high-Ni layered transition metal oxide (LiNi0.8Co0.1Mn0.1O2) via a simple wet process. By using residual Li on the surface of as-prepared LiNi0.8Co0.1Mn0.1O2 particles as a Li source, a non-stoichiometric Li-Zr-O compound can be successfully formed on the surface of LiNi0.8Co0.1Mn0.1O2 particles at a low temperature of 400 °C. The formation of an amorphous Li-Zr-O layer is beneficial in minimizing undesirable side reactions associated with residual Li at the surface and, by extension, improving the cycle performance and rate-capability of LiNi0.8Co0.1Mn0.1O2. The amorphous Li-Zr-O coated LiNi0.8Co0.1Mn0.1O2 exhibits a high reversible capacity of more than 190 mAh g−1 with improved cycle performance. This simple approach offers easy control of the surface characteristics of LiNi0.8Co0.1Mn0.1O2, improving the surface stability and enhancing the thermal stability.

A Ni-rich material (LiNi0.88Co0.09Mn0.03O2) was used as a cathode for Li-ion full cells to investigate the capacity fading behavior when the Ni content in the layered oxide cathode is very high. The morphology and compressive strength of the cathodes were analyzed after 1, 100, 200, and 300 full-cell cycles. A comparison of the results with those obtained for the LiNi0.8Co0.1Mn0.1O2 cathode revealed that the increased Ni content leads to further mechanical deterioration of the material upon cycling. The lattice parameter variation of the LiNi0.88Co0.09Mn0.03O2 electrode during cycling was measured using in situ X-ray diffraction analysis; the results showed that the variation of the lattice parameter of the LiNi0.88Co0.09Mn0.03O2 electrode was higher than that of the LiNi0.8Co0.1Mn0.1O2 electrode. The LiNi0.88Co0.09Mn0.03O2 electrode has a high specific capacity, indicating that more Li can be extracted from the electrode, which leads to the increased changes in the lattice parameter. Consequently, the high-Ni-containing electrode exhibits degraded mechanical and surface stabilities, as evidenced by observation of microcracks, a decrease in compressive strength of secondary particles, and increased internal pressure of the cells. Therefore, the mechanical and surface stability issues should be carefully considered when Ni-rich layered oxide cathode materials are used in Li-ion full cells.

Although magnesium batteries have received a great deal of attention as a promising power source, the native oxide layer on the Mg surface significantly impedes practical applications, because of the sluggish kinetic behavior of Mg-ion deposition and dissolution. Here, a new approach to improve electrochemical reactivity of Mg anode is proposed, based on chemical pretreatment of the Mg anode using a titanium complex, Ti(TFSI)2Cl2, that effectively removes the native oxide layer on the Mg anode surface. The pretreatment of the Mg anode by Ti(TFSI)2Cl2 remarkably decreases the binding affinity between Mg and O via the formation of a multicoordinate complex (Mg–O–Ti). Thereafter, a series of chemical reactions cleave the Mg–O bonds, resulting in a fresh Mg surface. This creates a cell comprised of the Ti(TFSI)2Cl2-pretreated Mg anode, glyme-based electrolytes, and cathode material that exhibits reversible electrochemical behavior at the electrode/electrolyte interface, resulting in practical applicability an...

The power characteristics of lithium-ion batteries (LIBs) are crucial for the advent of commercialized, high-power applications, such as electric vehicles. Through both first-principles multiscale simulations and experiments, here, we present fundamental understanding on the power characteristics of the high-voltage spinel cathode correlated with its elastic softness and phase transformation in nanodomains for high-power LIBs. Atomic models of LiNi0.5Mn1.5O4 and LiNi0.5Mn1.5−xTixO4 are developed for multiscale phase field modeling based on structural information for the as-prepared nanopowders. The combined computational and experimental investigations suggest that the thermodynamic phase stability of LiNi0.5Mn1.5O4 can be effectively enhanced by the incorporation of Ti into the structure without any change to the redox mechanism. Ti incorporation provides a faster ionic mobility and the improved phase stability because of the reinforced Ti4+–O bonds. Based on the multiscale phase transformation kinetics, LiNi0.5Mn1.5−xTixO4 exhibits an enhanced elastic softness and slower phase separation than LiNi0.5Mn1.5O4 in the nanodomain during Li+ insertion and extraction. Such characteristics are mainly responsible for the improved electrochemical performance at higher current rates, as confirmed by electrochemical experiments. This fundamental understanding of the power characteristics with respect to the correlations with elastic softness and phase transformation will provide a guideline to develop and design advanced materials for high-power LIBs.

Solid electrolytes are key to the evolution of all-solid-state lithium batteries as next-generation energy storage systems. High ionic conductivity and stability of solid electrolytes are critical requirements for designing reliable all-solid-state lithium batteries. Perovskite-type lithium lanthanum titanates Li3xLa(2/3)−x□(1/3)−2xTiO3 (LLTOs) have received much attention as a potential inorganic solid electrolyte to replace current organic liquid electrolytes; however, the practical use of LLTOs is limited by their low total conductivity. With the aim of improving the ionic conductivity, we investigated a correlation between the microstructures and Li+ conducting properties of LLTO perovskites. We show that the total conductivity of LLTOs is dominated by the domain boundary resistance, and the synthesis condition of the electrolyte (sintering temperature and Li concentration) has a crucial role in modifying the microstructure and composition of the domain boundaries to significantly reduce the boundary resistance. By controlling the sintering temperature and Li content, in particular, a total Li+ conductivity as high as 4.8 × 10−4 S cm−1 can be achieved at room temperature. The findings of this study would be essential in understanding Li+ conducting behaviors and in developing highly conductive perovskite-type LLTO solid electrolytes.

All-solid-state batteries (ASSBs) are gaining prominence for their ability to overcome the intrinsic drawbacks of conventional liquid-based counterparts, such as electrolyte leakage, flammability, and limited voltage window. Nevertheless, ASSBs have so far been mainly investigated using lab-scale dry mixing processes and therefore suffer from limitation of scalability and agglomeration of active particles in the composite electrodes. Here, we report a systematic investigation on ASSBs fabricated by a solution-based casting process. By screening a wide range of binders and solvents, acrylonitrile butadiene rubber and para-xylene were a suitable binder and solvent, respectively, compatible with sulfide glass-ceramic solid electrolyte. This binder-solvent combination facilitates homogeneous dispersion of the solid electrolyte in the slurry and electrolyte layer, offering high adhesion between electrode materials and comparable lithium ionic conductivity to that of the dry mixing-based counterpart. When solution-based casting processes were adopted for both electrolyte and composite cathode (containing LiNi0.8Co0.1Mn0.1O2) layers, the solution-processed cell exhibits decent performance in rate capability and cyclability due to higher homogeneity of the electrode components, originating from the appropriate combination of solvent and binder.

Recently, the substitution of inactive elements has been reported as a promising strategy for improving the structural stability and electrochemical performance of layered cathode materials for sodium-ion batteries (SIBs). In this regard, we investigated the positive effects of inactive Ti substitution into O3-type NaFe0.25Ni0.25Mn0.5O2 based on first-principles calculations and electrochemical experiments. After Ti substitution, Na[Ti0.03(Fe0.25Ni0.25Mn0.5)0.97]O2 exhibits improved capacity retention and rate capability compared with Ti-free NaFe0.25Ni0.25Mn0.5O2. Such an improvement is primarily attributed to the enhanced structural stability and lowered activation energy for Na+ migration, which is induced by Ti substitution in the host structure. Based on first-principles calculations of the average net charges and partial densities of states, we suggest that Ti substitution effectively enhances the binding between transition metals and oxygen by increasing the oxygen electron density, which in turn lowers the energy barrier of Na+ migration, leading to a notable enhancement in the rate capability of Na[Ti0.03(Fe0.25Ni0.25Mn0.5)0.97]O2. Compared with other inactive elements (e.g., Al and Mg), Ti is a more suitable substituent for improving the electrochemical properties of layered cathode materials because of its large total charge variation contributing to capacity. The results of this study provide practical guidelines for developing highly reliable layered cathode materials for SIBs.

All-solid-state lithium-ion batteries (ASLBs) employing sulfide solid electrolytes are attractive next-generation rechargeable batteries that could offer improved safety and energy density. Recently, wet syntheses or processes for sulfide solid electrolyte materials have opened opportunities to explore new materials and practical fabrication methods for ASLBs. A new wet-chemical route for the synthesis of Li-deficient Li

A potential solid electrolyte for realizing all-solid-state battery (ASB) technology has been discovered in the form of Li10 GeP2 S12 (LGPS), a lithium superionic conductor with a high ionic conductivity (≈12 mS cm-1 ). Unfortunately, the achievable Li+ conductivity of LGPS is limited in a sheet-type composite electrode owing to the porosity of this electrode structure. For the practical implementation of LGPS, it is crucial to control the pore structures of the composite electrode, as well as the interfaces between the active materials and solid- electrolyte particles. Herein, the addition of an ionic liquid, N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Py14 ][TFSI]), is proposed as a pore filler for constructing a highly reliable electrode structure using LGPS. [Py14 ][TFSI] is coated onto the surface of LGPS powder through a wet process and a sheet-type composite electrode is prepared using a conventional casting procedure. The [Py14 ][TFSI]-embedded composite electrode exhibits significantly improved reversible capacity and power characteristics. It is suggested that pore-filling with [Py14 ][TFSI] is effective for increasing contact areas and building robust interfaces between the active materials and solid-electrolyte particles, leading to the generation of additional Li+ pathways in the composite electrode of ASBs.

We report the failure mechanism of a Ni-rich layered cathode material (LiNi0.8Co0.1Mn0.1O2) in Li-ion full cells. Laminated pouch-type full cells were cycled 300 times, after which the cells exhibited 16.3% capacity fading. After 1, 100, 200, and 300 cycles, each full cell was disassembled and the cathode was investigated via a half-cell test, X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). XRD analysis showed loss of the active lithium source in the cathode, and FE-SEM observation exhibited traces of mechanical failure in the Ni-rich secondary particles. Particle strength measurements on the cathode materials by applying compressive force demonstrated that the mechanical strength of particles significantly weakened after full-cell cycling. Thus, the capacity of the Ni-rich cathode may deteriorate during full-cell cycling because of decreases in compressive particle strength. This issue should be considered in materials preparation processes.

(Trimethylsilyl)methanesulfonate (TMSOMs), functionalized with task-specific chemical moieties, is proposed as an interface-stabilizing additive to improve the electrochemical performance of 5V-class layered over-lithiated oxides (OLOs). TMSOMs offers a great opportunity to enhance the interfacial stability of an OLO material by providing an effective protective layer composed of SO3 and O Si functional groups after its electrochemical oxidation over 4.0 V (vs. Li/Li+), which remarkably reduces the internal pressure of the cell associated with electrolyte decomposition. As a result, the cell employing TMSOMs affords excellent capacity retention (92.8% at 100 cycles) together with considerable rate performance, negligible transition metal dissolution, and stable high temperature performance based on its enhanced interfacial stability. These results are attributed to the synergistic effects of the SO3 and O Si functional groups that once the sulfonic ester-based protective layer is developed on the electrode surface, it effectively mitigates decomposition of the electrolyte, while the O Si functional groups readily scavenge fluoride species in the electrolyte, leading to outstanding interfacial stability for the OLO material. On the basis of spectroscopic evidence, a comprehensive mechanism for the action of TMSOMs is suggested considering the specific role of each functional group.

Lithium ion batteries are encountering ever-growing demand for further increases in energy density. Li-rich layered oxides are considered a feasible solution to meet this demand because their specific capacities often surpass 200 mAh g−1 due to the additional lithium occupation in the transition metal layers. However, this lithium arrangement, in turn, triggers cation mixing with the transition metals, causing phase transitions during cycling and loss of reversible capacity. Here we report a Li-rich layered surface bearing a consistent framework with the host, in which nickel is regularly arranged between the transition metal layers. This surface structure mitigates unwanted phase transitions, improving the cycling stability. This surface modification enables a reversible capacity of 218.3 mAh g−1 at 1C (250 mA g−1) with improved cycle retention (94.1% after 100 cycles). The present surface design can be applied to various battery electrodes that suffer from structural degradations propagating from the surface., Surface modification of high-capacity lithium-rich layered oxides for improved capacity retention is an active area of battery materials research. Here authors demonstrate lithium-rich layered surfaces with a framework matching the host's, but with nickel atoms regularly arranged between layers.

We propose the use of a rosin-embedded poly(acrylic acid) binder, PAA-Rosin, to improve the cycling performance of silicon/graphite composites in lithium-ion batteries. Rosin, which is a natural product derived from pine trees, is chemically bonded with a rigid PAA polymer, which affords additional adhesion and elasticity of the PAA backbone, resulting in an effective binder with optimal properties. The hybridization of PAA-Rosin is achieved through an efficient one-step process, and the chemical structures of the components are systematically confirmed. In terms of the cycling performance, the cell based on PAA-Rosin shows excellent specific capacity retention (65.2%) with superior utilization of silicon/graphite composites even after 200 cycles. In addition, the PAA-Rosin electrode exhibits excellent specific capacity as well as remarkable capacity retention in bending tests. We demonstrate that the remarkable electrochemical characteristics of PAA-Rosin can be attributed to improved electrode uniformit...

In lithium-ion batteries (LIBs) comprising spinel cathode materials, the dissolution of transition metals (TMs) in the cathodes causes severe cyclic degradation. We investigate the origin and mechanism of surface TM dissolution in high-voltage spinel oxide (LiNi0.5Mn1.5O4) nanoparticles to find a practical method for its mitigation. Atomic structures of the LiNi0.5Mn1.5O4 surfaces are developed, and the electronic structures are investigated by first-principles calculations. The results indicate that titanium is a promising dopant for forming a more stable surface structure by reinforcing metal–oxygen bonds in LiNi0.5Mn1.5O4. Experimentally synthesized LiNi0.5Mn1.5O4 with titanium surface doping exhibits improved electrochemical performance by suppressing undesirable TM dissolution during cycles. The theoretical prediction and experimental validation presented here suggest a viable method to suppress TM dissolution in LiNi0.5Mn1.5O4.

Hydrated materials contain crystal water within their crystal frameworks and can exhibit extraordinary properties as a result. However, a detailed understanding of the mechanism involved in the hydration process is largely lacking, because the overall synthesis process is very difficult to monitor. Here, we elucidate how the insertion of crystal water mediates an anomalous spinel-to-Birnessite phase transition during electrochemical cycling in aqueous media. We find that, at the initial stage of the phase transition, crystal water is inserted into the interlayer space between MnO6 layers in the form of a hydronium ion (H3O+). The H3O+ insertion is chemically driven in the reverse (reducing) direction to the applied anodic (oxidizing) electric field, stabilizing the structure and recovering the charge balance following the deinsertion of Mn2+. A comparative investigation using various electrolyte solutions revealed that the H3O+ insertion competes with the insertion of other ionic charge carriers (Li+, Na+...

In this study, manganese orthophosphate (Mn 3 (PO 4 ) 2 ) is investigated as a new coating material for the Ni-rich LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode with the aim of improving its thermal properties. A sol–gel process is employed to achieve a uniform coating of nano–sized crystalline Mn 3 (PO 4 ) 2 . The coated electrode is found to exhibit an improved rate capability at high current drain, and cycle performance is enhanced at a high temperature of 60 °C. The effect of the Mn 3 (PO 4 ) 2 coating thus formed is further investigated by AC impedance spectroscopy, the results of which confirm that interfacial impedance is significantly decreased even in the initial cycles, and the growth of impedance is successfully suppressed during progressive cycles. The thermal stability of LiNi 0.6 Co 0.2 Mn 0.2 O 2 is also improved by the Mn 3 (PO 4 ) 2 coating, because of the high structural stability attributed to strong PO 4 covalent bonds. On the basis of these results, the Mn 3 (PO 4 ) 2 coating is proposed as a viable surface modification method for the enhancement of the electrochemical and thermal properties of LiNi 0.6 Co 0.2 Mn 0.2 O 2 .

A Ge/GeO 2 composite embedded in a carbon matrix (Ge/GeO 2 /C) is synthesized using a one-step mechanical ball-milling method, and its potential as a Li-ion battery anode material is evaluated. Characterization using scanning electron microscopy and transmission electron microscopy reveal that the uniformly distributed germanium and oxygen elements are embedded in the carbon matrix. In situ X-ray diffraction analysis provides insight into the complex conversion reaction as well as the Li–Ge alloy reaction. The Ge/GeO 2 /C composite exhibits a fairly high capacity of 915 mAh g −1 up to 50 cycles (with good cycling and a high rate capability). The improvement in the electrochemical performance arises from the synergistic effects of the reduced particle size, conductive carbon matrix, and catalytic function of Ge to mitigate mechanical strain and provide an efficient network for electron transfer.

Nickel-rich lithium nickel cobalt manganese oxides have received considerable attention as a promising cathode material, however, they have suffered from poor interfacial stability, especially at high temperature. Here, we suggest a bi-functionalized divinyl sulfone that enhances the applicability of a nickel-rich cathode via stabilization of the electrolyte–electrode interface. The divinyl sulfone forms a protective layer on the cathode surface by electrochemical oxidation reactions and this greatly decreases the internal pressure of the cell via stabilization of the Ni-rich cathode–electrolyte interface. The cell controlled with divinyl sulfone shows remarkable cycling performance with 91.9% capacity retention at elevated temperature even after 100 cycles. Additional electrode analyses and first-principles calculations provide critical spectroscopic evidences to demonstrate the combined effects of the sulfone and vinyl functional groups. Once the divinyl sulfone is electrochemically oxidized, the vinyl functional groups readily participate in further stabilizing sulfone-based solid electrolyte interphase intermediates and afford a durable protective layer on the nickel-rich electrode surface.

All-solid-state batteries (ASB) have received great attention as a next generation power source due to its safe characteristics with non-flammable solid electrolyte. Whole battery reactions are occurred in solid-state Li+ migration in ASB, therefore the well-contacted interfacial area is critical for battery performance. Especially for ASB with high energy density, casting process is suitable to form a large sized sheet of electrode and electrolyte. When electrode and electrolyte sheets are fabricated by conventional cold pressing, sulfide solid electrolyte is favorable to form a contact area effectively due to its elastic powder character compared to oxide. However, sulfide solid electrolyte is chemically unstable with humidity in air. It easily generates H2S gas that is toxic and hazardous. Residual Li2S and bridge sulfur in structure are known as main cause of H2S generation. The ionic conductivity is also decreased by the decomposition of solid electrolyte by undesirable H2S generation. In this study, zeolite were used as additive for H2S scavenger. 5 wt% of zeolite additive was mixed with argyrodite-type Li6PS5Cl, then exposured in moisture air (Rh 50%). The amount of H2S gas generation was greatly reduced by introducing zeolite additive. Decease of ionic conductivity after air exposure is also suppressed by zeloite additive. It also affect to cell performance such as specific capacity and cycle performance. On the basis of these results, adding H2S scavenger is proposed as a visible method for enhancement of air-stability of sulfide solid electrolyte. The detailed results will be discussed at the meeting.

Green bodies of earthenware tile were prepared from a mixture of earthenware tile powder and SiC as forming agents by applying a conventional process. Granule powder for tile samples was prepared using the spray drying method with commercial earthenware raw material with a quantity of SiC of 0.3 wt%. The applied pressure was 250 kg·f/㎡ and the firing temperature was 1050-1200℃. The effects of the SiC particle size and sintering temperature on the open porosity and total porosity were investigated and the correlative mechanism was also discussed. While total porosity was not significantly changed by decreasing the SiC particle size, the open porosity showed a gradual decrease, which represents an increase of the closed porosity. As the sintering temperature increased, coarsening was made among the pores due to excessive oxidation. The volume shrinkage and bending strength were demonstrated for the sintered tile samples. The sintered bulk density was also measured to determine the weight reduction value.

A surface coating of SiO2 is applied to a Ni rich LiNi0.6Co0.2Mn0.2O2 cathode material in a bid to improve its electrochemical and thermal properties. A uniform coating is achieved through a wet process using nano-sized SiO2 powder, and though the coated electrode is found to exhibit a reduced rate capability, its cycle performance at a high temperature of 60 °C is greatly enhanced. The effect of this SiO2 coating is further investigated by electrochemical impedance spectroscopy, which confirms that it suppresses the growth of interfacial impedance during progressive cycles. The SiO2 coating also demonstrates good HF scavenging ability, producing a subsequent reduction in the degradation of the active core material. The thermal properties of LiNi0.6Co0.2Mn0.2O2 are also improved by the SiO2 coating due to a reduction in the direct contact between the electrode and electrolyte. On the basis of these results, SiO2 coating is considered a viable surface modification method for improving the electrochemical and thermal properties of LiNi0.6Co0.2Mn0.2O2.

We compared four types of ZIF-8 with varying sizes and shapes to determine their thermal-structural stability and derive appropriate thermal activation conditions and correlation between structural characteristics and adsorption properties. Under air, the ZIF-8 phase for all the samples was converted completely into the zinc oxide phase above ∼300 °C, though thermalgravimetric analysis (TGA) indicated that the original structure was stable to ∼300–350 °C. Longer exposures (∼30 d) suggested that thermal activation at ∼200 °C was appropriate for the removal of guest and/or solvent molecules under air without structural damage. Despite no noticeable change in X-ray diffraction (XRD) patterns after activation at 250 °C under air, the resulting BET surface areas and CO2 adsorption amounts (at 1 bar and 30 °C) of ZIF-8s were reduced to ∼44–54 and ∼72–87%, respectively, as compared to those of appropriately activated ZIF-8s. It appears that after the activation at 250 °C under air, some Zn and N atoms were disso...