一般財団法人材料科学技術振興財団　MST Product Lineup

When investigating the degradation mechanisms of secondary batteries, it is important to analyze the deposits on the electrode surface. At MST, we conduct TOF-SIMS measurements under controlled atmospheric conditions, allowing us to evaluate the chemical state of the electrode's outermost surface without alteration due to exposure to the atmosphere. Additionally, by consistently performing measurements from charge-discharge cycle tests to the electrode surface, we can examine the correlation between the state of charge-discharge and the condition of the deposits on the electrode surface.

A degradation test was conducted on a battery cell made with LiCoO2 as the positive electrode, graphite as the negative electrode, and LiPF6/EC:DEC as the electrolyte, which was left in a constant temperature chamber at 60°C in a charged state of 4.2V for about one week. After that, the cell was disassembled and cleaned in an Ar atmosphere, and TOF-SIMS analysis of the negative electrode graphite was performed. Before the test, fragments derived from the binder and electrolyte salt were confirmed, and after the test, fragments such as Li3PO4 and PF3O, which are believed to have been generated due to the degradation of the electrolyte salt, as well as fragments from Li2CO3, were observed. Additionally, the detection of Co suggests the possibility of leaching of the positive electrode active material.

It is possible to measure the resistance of electrode materials in lithium-ion batteries using SSRM (Scanning Spreading Resistance Microscopy). In electrode composites made up of components with different resistance values, it may be possible to confirm the mixing ratio of various materials as well as the presence of electrically active and inactive active materials. Additionally, by combining shape measurements such as AFM and elemental analysis, a comprehensive evaluation can be achieved.

Silicon (Si) is one of the candidates for high-capacity anode active materials, but it is said to suffer from severe cycle degradation due to the very large volume changes during charge and discharge. We dismantled and observed the Si anode before and after charging under controlled atmospheric conditions. Furthermore, we created cross-sectional observation samples using the FIB micro-sampling method and conducted shape observation and EELS measurements with a Cs-corrected STEM device to evaluate the condition of the Si electrode and the distribution of Li within the electrode.

The development of lithium-ion secondary batteries faces challenges such as improving performance, extending lifespan, and enhancing reliability. To address these challenges, it is important to understand the degradation mechanisms of the batteries. In this study, we conducted a heating degradation test to evaluate the degradation mechanisms caused by temperature. After the heating degradation test, we assessed samples that showed significant capacity reduction using LC/MS/MS for the electrolyte, TOF-SIMS for the anode surface, and FIB-TEM+EDX for the cross-section of the anode.

A comparison of the electrolyte of lithium-ion secondary batteries composed of organic solvents and supporting salts containing Li before and after degradation was conducted using LC/MS analysis. As a result, components believed to be reaction products of LiPF6 and the electrolyte were detected. Furthermore, by analyzing characteristic components after degradation using LC/MS/MS, it was possible to estimate the components that are thought to have been generated by the degradation test.

Lithium-ion secondary batteries have excellent characteristics among secondary batteries, but there are various challenges in their development, such as increasing output, capacity, and lifespan. This time, we will introduce a case where the composition of sheet-like active materials for the positive electrode was evaluated with high precision using ICP-MS analysis.

Si is one of the candidates for high-capacity negative electrode active materials, but it is said to suffer from severe cycle degradation due to very large volume changes during charge and discharge. In this study, to confirm the state of the Si negative electrode after charging, we disassembled it under a controlled atmosphere environment and performed cooling FIB processing, followed by observing the cross-sectional shape using SEM. When observing the cross-section at room temperature, significant damage such as film contraction, roughness of the observation surface, and pore formation was observed. In contrast, by conducting the observation while cooling, we were able to suppress the alteration of the Si negative electrode and evaluate the original shape of the sample.

The separator, which is a key component material of batteries, significantly influences the characteristics and safety of the battery due to its porosity, shape, and other factors. Currently, mainstream polymer materials such as polyethylene (PE), polypropylene (PP), or their composites have low softening points, with PE around 125°C and PP around 155°C. This report presents a case study where the cooling of a low softening point PP separator was conducted to suppress degradation and evaluate its structure.

The electrodes of lithium-ion secondary batteries are very significant constituent materials that greatly influence the performance and reliability of the battery, such as its capacity. By performing ion polishing (IP) processing on the electrode materials after charge-discharge cycle testing under controlled atmospheric conditions, we can accurately observe them while minimizing degradation due to atmospheric exposure. In this instance, we will present a case that verifies the effect of atmospheric control on the positive electrode materials of lithium-ion secondary batteries after charge-discharge cycles by comparing the results of SEM observations after IP processing.

Regarding the positive electrode of lithium-ion secondary batteries, it is possible to visualize the distribution of crystal grains insulated from the surroundings and the active materials whose conductivity has decreased due to degradation by mapping their shape and conductivity. In this case study, we present the results of estimating the material distribution through SSRM measurements conducted on a cross-section of the positive electrode of a lithium-ion secondary battery prepared by mechanical polishing, along with statistical processing. Measurement method: SSRM Product field: Secondary batteries Analysis purpose: Composition distribution evaluation, shape evaluation, degradation investigation For more details, please download the materials or contact us.

Using data from Slice&View (a method that repeatedly performs FIB processing and SEM observation to obtain dozens of continuous images), it is possible to calculate the volume of particles and other micron-sized objects. This allows us to obtain information such as the presence ratio and average volume of each substance within a certain volume. In this case study, we will introduce an example where the volume of active material was calculated from the Slice&View analysis results of a lithium-ion secondary battery cathode, and the presence ratio was determined.

In recent years, as hybrid and electric vehicles have been becoming more widespread, there is a growing demand for larger and higher-performance lithium-ion secondary batteries for their power supply. To develop high-capacity positive electrode materials, it is crucial to identify the correlation between composition, structure, and electrochemical properties. By clarifying the electronic states of metal elements and their local structures in positive electrode materials through XAFS analysis using synchrotron radiation, it is possible to gain insights into the correlation between composition, structure, and electrochemical properties.

This is an example of evaluating the organic solvent components of an electrolyte using GC/MS analysis. The measurement of the electrolyte in lithium-ion secondary batteries revealed that the main components of the organic solvents are ethylene carbonate (EC) and propylene carbonate (PC). Other components detected included diethyl carbonate (DEC) and sulfur compounds, with the latter possibly originating from additives.

Lithium-ion secondary batteries use a wide variety of materials, ranging from metals and inorganic substances to organic materials, and from solids to liquids. The physical properties and combinations of each material significantly reflect the characteristics and reliability of the device, making accurate analysis and evaluation of the materials necessary. In this study, the anode of the lithium-ion secondary battery was measured using pyrolysis GC/MS (pyro-GC/MS), and it was found that the binder material is based on SBR (styrene-butadiene latex). Additionally, decomposition products of the binder and aromatic substances presumed to be reaction products were also detected.

The electrodes of lithium-ion secondary batteries are composed of active materials, conductive additives, and binders for both the positive and negative electrodes. The characteristics of the battery, such as capacity and reliability, are greatly influenced by the combination of materials, mixing ratios, filling density of active materials, and voids. Among these, FIB-SEM observation, which allows for processing and observation in a completely dry atmosphere, is very effective for observing filling density and voids. Furthermore, by conducting three-dimensional observation (Slice & View), it is possible to directly evaluate the condition of the electrodes.

In AES (Auger Electron Spectroscopy), it is possible to perform elemental mapping (surface analysis) at sub-micron levels, allowing for clear confirmation of the elemental distribution in ternary materials (Co, Mn, Ni). Additionally, the distribution of carbon derived from binders and conductive additives can be measured with high sensitivity. In this study, a series of processes for the positive electrode active material were conducted in an atmosphere-free environment (inert gas atmosphere) until the introduction of the equipment, minimizing alterations during measurement. As a result, it was suggested that larger particles are LiCoO2, while smaller particles are LiCoxMnyNizO2 and LiMn2O4, indicating a non-uniform distribution of particles. Measurement methods: AES・SEM Product field: Secondary batteries Analysis purpose: Composition evaluation, identification, composition distribution evaluation For more details, please download the materials or contact us.

As a result of evaluating the surface of lithium-ion secondary battery anodes, which showed a decrease in capacity, without exposure to the atmosphere, a coating layer containing approximately 100-200 nm of Co was confirmed, and it was found that Co is in a metallic state. Applicable observation methods: FIB-TEM, SEM Surface analysis: SIMS, XPS, AES, TOF-SIMS Other structural evaluations are also possible. Measurement methods: SEM, FIB, TEM, XPS, EDX Product field: Secondary batteries Analysis objectives: Evaluation of chemical bonding states, shape evaluation, composition evaluation, identification For more details, please download the materials or contact us.

Lithium-ion secondary batteries have excellent characteristics among secondary batteries and are widely used as power sources for various portable devices. However, there are still various challenges remaining, such as increasing output, capacity, longevity, and reliability. Comprehensive evaluation of battery materials is possible using various analytical methods.

By conducting sample pretreatment, transportation, and measurement under a high-purity inert gas atmosphere, it is possible to evaluate while suppressing surface oxidation and moisture adsorption. ■Examples of Application - Semiconductor electrode materials Evaluation of peeling surfaces can be conducted while minimizing the effects of secondary contamination and oxidation. - Organic EL materials Working in an inert gas atmosphere from the moment of opening prevents material degradation. - Battery materials such as Li If processing in a N2 atmosphere is not possible for materials like Li, treatment can be performed in an Ar atmosphere as an alternative.

As exemplified by the separators used in lithium-ion secondary batteries, the microstructure of materials, such as porosity and shape, significantly influences the characteristics and functions of products. When materials have a low softening point, such as resins or polypropylene (PP), they may be damaged by electron beam irradiation during observation, leading to changes in their original structure. We will present a case where ultra-low acceleration SEM observation at an acceleration voltage of 0.1 kV was used to suppress alteration and evaluate the surface morphology of the sample in detail.

The electrolyte of lithium-ion secondary batteries is known to decompose and gasify due to repeated charging and discharging. By using GC-TCD and GC/MS, the decomposed gas components can be detected with high sensitivity. GC-TCD can analyze the composition ratios of eight components (H2, O2, N2, CO, CH4, CO2, C2H4, C2H6), while GC/MS can qualitatively analyze various decomposition products. We also support gas analysis in not only laminate-type cells but also coin-type and prismatic cells, as well as cells using ionic liquids.

In lithium-ion secondary batteries, the SEI layer (solid electrolyte interface) is a significant factor affecting the battery's lifespan, and it is important to understand the chemical species of Li contained within it. Li itself has a small chemical shift, making direct evaluation difficult; however, by performing waveform analysis to separate the states of the bonding partner elements (C, O, F, P), it is possible to calculate the presence ratio of Li in different bonding states. An evaluation of the state of Li before and after cycle testing revealed that after the test, the presence ratios of Li2CO3 and Li-POxFy increased compared to before the test.

Samples such as lithium-ion secondary battery materials that deteriorate when exposed to the atmosphere, and organic materials that change due to heat during processing and observation, are difficult to observe structurally using TEM under normal environmental conditions. Our organization has established a system that controls the atmosphere to minimize exposure to air, and further cools the samples for processing, observation, and analysis, allowing us to prepare TEM thin film samples while preserving the original structure of the samples for observation and analysis.

Samples such as lithium-ion secondary battery materials that deteriorate when exposed to the atmosphere and organic materials that change due to heat during processing and observation have made it difficult to observe their original structures using TEM and SEM. By observing them with a high-resolution SEM equipped with FIB under controlled atmospheres without exposure to the air, we can understand the original states of particles and electrolytes. Additionally, it is compatible with cooling, which helps to suppress deterioration caused by heat.

In XPS analysis, the binding state evaluation of the material surface is conducted by observing the energy of photoelectrons obtained through X-ray irradiation. It allows for the assessment of whether metal elements are in an oxidized state, and for elements with significant energy shifts (chemical shifts) due to oxidation, it also enables the evaluation of the presence and proportion of multiple valences. Below are the main metal elements and oxides for which multiple valence evaluations are possible.

The electron diffraction method using an electron microscope is classified into three types based on the way the electron beam is incident on the sample. The characteristics of each type and examples of data are presented. It is necessary to choose the appropriate method according to the size of the evaluation object and the analysis purpose.

Silicon oxide films are widely used as gate dielectrics in MOS devices and as anode materials in lithium-ion secondary batteries, but it is known that the presence of intermediate oxides and the bonding states at the interface have a significant impact on device characteristics. XAFS measurements using synchrotron radiation can detect information from a depth of several tens of nanometers from the sample surface, allowing for non-destructive analysis of the structure and bonding states in both bulk and at the interface. This document presents a case study investigating the presence of intermediate oxides in silicon oxide films using XAFS.

Carbon materials, widely used in industrial components and medical devices, have different properties depending on their structure and crystallinity, making it important to evaluate their state. This document presents evaluation examples using high-sensitivity and high-spatial-resolution Raman spectroscopy. The distribution of the crystalline state of graphite, a carbon material, was visualized through mapping. It allows for a visual capture of the quantity of defects, whether high or low.

The Karl Fischer titration method is a way to evaluate the moisture content, and the method of introducing the sample into the device varies depending on the properties of the sample. Here, we will introduce two sample introduction methods for titration.

Graphene, a monolayer form of graphite, is expected to be applied in a wide range of fields such as batteries, transparent electrodes, and sensors due to its excellent properties, including toughness, high electrical conductivity, and high thermal stability. It is also said that the types and amounts of functional groups present on the surface vary depending on the manufacturing method, and clarifying its structure is an important point for improving performance. This case study introduces a comparison of the functional groups of two types of graphene using thermal decomposition GC/MS method.

By measuring the sample, it is possible to evaluate the crystal structure through the combination of results obtained and simulations. This document introduces a case study in which the crystal structure is discussed by comparing the results obtained from HAADF-STEM and EDX measurements on polycrystalline neodymium magnets with simulated images using the respective measurement conditions. The combination of measurement results and computational simulation results allows for a deeper understanding of the crystal structure.

Lithium-ion secondary batteries are widely used in devices such as smartphones and digital cameras. These batteries degrade through repeated charging and discharging, which can lead to the phenomenon of battery swelling. When investigating a battery that has experienced this phenomenon, there are concerns about reactions caused by gases or electrolytes accumulated inside, and since processing can be dangerous, it is necessary to confirm the internal structure non-destructively. In this case, the internal structure of a lithium-ion secondary battery that has undergone repeated charging and discharging was observed using X-ray CT.

TDS (Thermal Desorption Gas Analysis) is a method that allows for the confirmation of desorbed components and desorption temperatures while heating a sample in a vacuum (1E-7 Pa). Furthermore, by combining the results of TDS with GC/MS (Gas Chromatography-Mass Spectrometry), which can identify organic substances, it is possible to evaluate the desorption temperatures of specific desorbed components in a vacuum. Below, we present an example of a combined analysis of TDS and GC/MS conducted on graphene.

One of the causes of capacity degradation at the negative electrode of lithium-ion secondary batteries is the formation of a film called SEI (Solid Electrolyte Interphase), which is created by interfacial reactions between the active material and the electrolyte, resulting in various lithium salt compounds complexing on the surface of the active material. To improve battery performance, control over the composition, thickness, and chemical bonding state of the SEI film is required. This document presents examples of evaluations of the SEI film formed on the surface of carbon-based negative electrode active materials for automotive batteries using SEM, TEM, TEM-EELS, TOF-SIMS, and XPS. *For more details, please refer to the PDF document or feel free to contact us.*

In the charging and discharging process of lithium-ion secondary batteries, various phenomena occur near the interface with the electrolyte and the anode, including the formation of solvation, desolvation, the formation of electric double layers, and the de-insertion and insertion of Li ions. This document introduces a case where the ESM-RISM method, which combines the Effective Shielding Medium Method and the Reference Interaction Site Model, was used to evaluate the microscopic distribution of electrolyte components through simulation. This method is expected to be applicable not only to secondary batteries but also to a wide range of fields, including fuel cells, various catalytic reactions, and the corrosion and protection of metal surfaces. 【Contents】 ■ Overview ■ Data - Schematic diagram of the anode (graphite) - electrolyte interface - Solvation structure in the electrolyte - Electric double layer near the anode - electrolyte interface *For more details, please refer to the PDF document or feel free to contact us.

In HAXPES, it is possible to obtain information from deep positions (up to about 50 nm) from the sample surface. Furthermore, by using a two-dimensional detector for angle-resolved measurements, data obtained at a wide range of photoelectron emission angles can be divided into information corresponding to different angles, that is, varying detection depths. This allows for a comparison of depth-resolved bonding states to greater depths than XPS in a non-destructive manner. It is effective for evaluating materials where state changes extend not only to the surface but also into the bulk.

Lithium-ion polymer batteries are widely used in everyday products such as mobile batteries and electronic devices. This document presents a case study of analyzing a laminated lithium-ion polymer battery using X-ray CT. By using X-ray CT, it is possible to observe the internal structure of a 20mm x 40mm battery without destruction and to check for the presence and location of foreign objects or voids measuring a few micrometers. For more details, please download the document or contact us.

Rietveld analysis is a method for analyzing measurement data from XRD (X-ray diffraction) and neutron diffraction. In addition to identifying lattice constants and space groups using existing methods, it is possible to obtain more detailed crystallographic information, such as atomic arrangements within the unit cell, if there is a crystal structure model (candidate) for the sample.

Nuclear Magnetic Resonance Spectroscopy (NMR) is an analytical method that can obtain various information about molecular structure, intermolecular interactions, and molecular mobility, targeting various compounds including organic substances. This document presents examples of measurements conducted with a super low-temperature probe, which achieved higher sensitivity compared to a general-purpose room temperature probe.

We provide suitable analysis menus for essential components of EVs, including onboard batteries and devices.

Lithium hexafluorophosphate (LiPF6), the main component of the electrolyte in lithium-ion batteries, is known to undergo hydrolysis upon reaction with moisture, generating fluoride ions. This document presents a case where the concentration of fluoride ions produced by the atmospheric exposure of the electrolyte (1M LiPF6, EC:EMC = 3:7 v/v) was evaluated using 19F-NMR, which allows for absolute quantification without the use of standard compounds. Measurement method: NMR Product field: Secondary batteries and electronic components Analysis purpose: Failure analysis, defect analysis, degradation investigation For more details, please download the document or contact us.

Aromatic azo compounds with reduction activity are attracting attention as low-environmental-impact next-generation organic active materials that can replace the currently dominant metal active materials in alkaline ion batteries and redox flow batteries. Evaluating battery performance is useful through the examination of the electronic structure and redox properties of materials using simulations in addition to experiments. This document presents examples of quantum chemical calculations of the reduction potential of azobenzene and its carboxylic acid derivative salts, as well as molecular orbital calculations. In this way, the electrochemical properties of materials can be estimated through simulations. Measurement methods: Computational science, AI, data analysis Product field: Secondary batteries Analysis purpose: Evaluation of chemical bonding states "For more details, please download the document or contact us."

In HAXPES, hard X-rays (Ga radiation) are used for excitation, which results in different positions of the Auger peaks compared to the Al and Mg radiation typically used in standard XPS measurements. Therefore, even in samples where the photoelectron peaks and Auger peaks overlap in Al and Mg measurements, this overlap can be avoided in Ga measurements, allowing for a detailed evaluation of the bonding states. This document presents the spectra of Kovar (an alloy of Fe, Ni, and Co) and GaN measured using Ga radiation (equipped with HAXPES) and Al and Mg radiation (equipped with XPS).

The electrolyte of lithium-ion secondary batteries can be qualitatively and quantitatively analyzed using GC/MS. In the example below, ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were identified as organic solvents, and vinylene carbonate (VC) was identified as an additive. It is also possible to determine the composition ratio of the solvents and the content of the additives. Additionally, other additives such as fluoroethylene carbonate (FEC) and ethylene sulfite (ES) can also be evaluated.