Electromagnetic Non-Destructive Non-Contact Methods & Device for Evaluation Nanostructured Electrode Materials and Electrode Structure of Li-Ion Batteries.

Abstract

Proprietary non-destructive non-contact (NDT) electromagnetic, holographic interferometry, gas discharge visualization, and combined methods, developed by Enerize, enable to evaluate properties of nano-structured powder of electrode materials, polymer and solid inorganic electrolytes, and interface of multi-layered electrode structures. Developed non-destructive testing methods & devices enable to optimize the technology, and quality of initial materials, components, and cells, including in-line control during battery production. These methods allow insure the safety and reliability of the batteries and reduce the cost of production Electromagnetic NDT inspection consists in estimation of the level of magnetic fields interaction between the primary and secondary transducers from the currents induced by the primary field in investigated object. Primary transducer creates magnetic field at alternating current passage on it. This magnetic field excites eddy currents in investigated object. Eddy currents create secondary magnetic field, which is directed towards the primary one, and the total field is less by the value of the secondary field. The value of secondary field depends on the value of induced primary eddy currents, and their value directly depends on the quality and controlled object properties. Thus, one can judge about controlled object quality by the value of summary magnetic field. Using these methods we can control without contact the following values: conductivity, defect availability, dielectric permeability, thickness and solve many other problems of non-destructive testing. The non-contact feature of these methods allows in-line quality control during synthesis of component materials as well as during production and final assembly of batteries, supercapacitors, solar cells, etc. Application of these systems results in improved product reliability and safety, while lowering overall manufacturing costs by reducing wastage and preventing defective components from being incorporated into the finished product. A number of mathematical tools are used for process description and modeling, for signal processing, and for generating properties control information based on analysis the dependences between the parameters the fields that are applied and the electro-physical characteristics the test article that measured. These include: mathematical descriptions of elastic waves in isotropic and anisotropic media; Maxwell’s and Laplace’s equations; mathematical tools for spectral transformations in different orthogonal bases; methods of defect identification and the processing and analysis of images using fuzzy logic and artificial neural networks.During presentation will be presented NDT methods and systems developed by Enerize for the following electromagnetic testing: determine specific conductivity, electromagnetic properties and composition of powdered materials, including nano powdered oxides and graphite for Li-ion batteries electrodes ; specific conductivity of thin films (transparent conductive oxides for solar cells, solid and polymer electrolytes, polymer membranes for fuel cells, etc.); non-contact electromagnetic testing to determine the interface resistance between current collector and active electrode mass; nondestructive determination of defects in multilayer structures based on combined ultrasonic and electromagnetic methods (e.g., “jelly-rolls” for batteries and supercapacitors) and other. The developed methods and equipment can be adapted from measurements of test articles or materials under static conditions to dynamic measurements during material synthesis. Enerize owns 14 US patents, 1 Great Britain patent, and numerous US patent applications in the area of Li-ion batteries, solar cells, and non-destructive non-contact testing..