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Energy storage : a global challenge proven by microtomograph

by Verona on 26 Jan 2021 at 11h28

The development of energy storage solutions, especially for batteries, has been one of the most active industrial fields for many years. The stakes are getting higher with the exponential growth of electric mobility, connected objects and means of communication.

Current Context of Energy Storage

There is one basic principle when talking about electrochemical battery: transforming electrical energy into chemical energy during charging and conversely to restore electrical energy during discharge. This tenet has been used in lead batteries for 150 years. Designed more than 30 years ago, Lithium-ion batteries are as for today the most widespread solution in various sectors. Its very high efficiency (3 times more power than a lead battery of the same weight) and the large number of cycles make it the most efficient solution.
Nevertheless, there are many issues to improve existing products: storage capacity, manufacturing cost, safety, ecological cost and of course life expectancy. The work detailed in this application note was focused on these last two points.

Introduction to Lithium - ion batteries

Lithium - ion batteries are used from cell phones to electric cars thus are becoming today's energy storage solution for various areas. Significant power as well as autonomy make these batteries the most widespread solution as for today. Nevertheless, many projects are currently underway, focusing on different aspects such as : storage capacity, security, ecological cost and of course life expectancy.

What is it ?  

Li-ion batteries are made up of a multitude of cells, each one being able of generating a few volts. Every cell is formed of two electrodes that will exchange ions, lithium in Li-ion batteries. The analysis on a very small scale of the chemical components of the electrodes is then an essential step to improve the performance of the batteries.

How does it work ? 

Conventional means of materials analysis often require the destruction of the sample and do not allow the evolution of a battery to be monitored over the charge and discharge cycles. In addition, these techniques provide two-dimensional information only, which is unsuitable for the analysis of a three-dimensional porous network
X-Ray micro-tomography provides a technical solution to this challenge. Understanding the mechanisms of electrode degradation over cycles, means visualizing:
- “In-situ” measurements: produce images during charge & discharge cycles
- 3D rendering results of the electrode on a submicron scale 
Work carried out by the MATEIS laboratory, equipped with an EasyTom 160, jointly with the National Institute for Scientific Research (INRS) in Varennes (Canada) has made it possible to improve the electrode manufacturing process and thus reduce electrode degradation during charge and discharge cycles.

In current race for improved energy storage solutions EasyTom Microtomograph is a key tool

The use of a laboratory microtomograph has been validated for the analysis of the microstructure. materials in Li-ion cells with Silicon electrode, both for ex situ analyses on an inert sample and for in situ experiments. It is thus possible to quantify with the EasyTom 160 the three-dimensional distribution of the Silicon in the electrode, and observe a number of degradation phenomena during a cycle.
This breakthrough enables laboratories and research centers to significantly accelerate their work while still relying on synchrotron sources when the limitations of the laboratory equipment are reached.