Lithium-ion rechargeable batteries are used in a wide range of applications, including mobile devices and automobiles. Particularly for the latter, there has been a lot of activity in the development of materials for high capacity, high output, and safety and reliability evaluation.
For active materials, it is important to evaluate the crystal structure of the polar surface, which influences the structure and intercalation of the bulk. In addition, organic solvent-based electrolytes and solid electrolytes are very important components for product characteristics and safety. In addition to this, we can perform electrical evaluation such as conductivity mapping to comprehensively evaluate the materials.
Examples
・Atomic resolution analysis of cathode materials for lithium-ion secondary batteries
・Precise structural analysis of powdered crystal materials by Rietveld analysis
・Molecular dynamics simulation of electrolytes for lithium-ion secondary batteries
・Investigation of dispersion of various materials constituting electrodes by evaluating their electrical conductivity
Atomic resolution observation of cathode materials for lithium-ion secondary batteries
This is an example of FIB processing and TEM analysis of LiCoO2 particles from a cathode material disassembled from a lithium-ion secondary battery without exposure to air under controlled atmosphere and cooling.The atomic arrangement was confirmed by STEM observation and EDX analysis while cooling down to -174℃.High-resolution analysis of materials with low thermal stability and crystalline materials that change in the atmosphere is also possible.
Precise structural analysis of cathode active materials by Rietveld method
This is an example of Rietveld analysis for powder X-ray diffraction data of Li(Ni,Mn,Co)O2, which is used as a cathode active material in lithium-ion batteries.The crystal structure model, which reproduces the actual powder X-ray diffraction data by simulation, enables us to precisely calculate the crystal structure parameters such as lattice constant, occupancy of each site, and ratio of cation mixing, and to consider the physical properties of materials based on these parameters.
Material distribution evaluation of cathode materials for lithium-ion batteries
By mapping the shape and conductivity of the cathode of a lithium-ion battery, it is possible to visualize the distribution of insulated grains and active materials whose conductivity is degraded by degradation.This case study introduces the results of SSRM measurement of the positive electrode of a lithium-ion battery by mechanical polishing and estimation of material distribution by statistical processing.
Cathode material conductivity mapping
Molecular dynamics simulation of electrolytes for lithium-ion batteries
The electrolyte used in lithium-ion batteries generally consists of a solvent and an electrolyte salt, and is considered to be a homogeneous system in the macroscopic view, but from the microscopic view, phenomena such as solvation occur. It is important to understand the local structure of lithium ion solvation and its reaction to the cathode and anode insertion in order to design high performance battery materials. In this document, we introduce a case study in which the microscopic structure of lithium ion solvation was evaluated by molecular dynamics simulation.
Click here to see the case studies of battery