AETC specializes in the production and custom development of materials for power sources such as batteries, fuel cells, electrochemical supercapacitors, and specialty paints/coatings.
We use a variety of battery materials in our production.
Spherical graphite is used as anode active material for lithium ion batteries. It can be uncoated, carbon coated, or doped with other elements. We produce materials with a tight size tolerance for high energy, high power, and hybrid applications of lithium ion batteries using processes developed by AETC. This is done with the use of the state-of-the-art equipment and most modern technologies.
Typically, a higher tap density results from a larger particle size. We hold a record tap density of 1.18 g/cm^3 with a d50 of 20 microns and d95 of less than 29 microns, which performed well for customers in a high energy lithium ion battery. Our smallest particle size has a d50 of 8 microns.
This development was revolutionary for natural crystalline flake graphite material, since, with standard technology, it is impossible to create a spherical product at less than 11-12 microns, 0.85 microns in uncoated form, featuring a high tap density.
When it comes to spheroidization, we recognize that some flakes are thick and some are thin. The mechanism for spheroidization will differ depending on aspect ratio of particles of feed material.
We can sort particles by size using our gravity separation method which does not involve screening. We are able to produce spherical graphite particles of precise cut with targeted d50 specified down to a singular micron.
We encourage customers to come to us to explore what can be done with their raw materials of natural or synthetic origins. We are the first to recognize that graphite is not as uniform as other minerals, so the successful development of spherical graphite can be performed with some deposits, but not others.
Materials for Conductivity Enhancement
In contrast to spherical graphite, conductive carbons have thin, sheet-like particles preferably with twisted edges and multiple breaks on the surface. Each break point becomes a contact point when such material is used as an electrically conductive diluent in active battery matrices. Irregular geometry of graphite particles becomes an additional pathway for the flow of electrons.
Four-point resistivity testing us to discover how beneficial a given powder is in ensuring efficient conductivity enhancement.
The conductive carbon is added to battery active material at a given percent loading. Conductive carbon is uniformly developed into the matrix by being subjected to compressive forces under the unidirectional load. This is useful, as it mimics the actual application in a battery without having to go through an exercise of making the latter. An electrical current is then run through and the resistance is determined. The lower the current, the higher the resistance.
It is in the battery makers’ interest to use as little carbon as possible. In a fixed volume of a cell, any carbon that comes out will be substituted for active material, giving cell a higher capacity.
Some materials are more conductive than others. Expanded graphite tends to offer higher conductivity in battery matrices than synthetic or natural crystalline flake graphite. We are able to take customers’ materials and produce batteries for them where your active material would be combined with an expanded graphite..
The ultimate proof of efficiency of a conductive additive comes with a cell build. We are able to produce a wide variety of cell types and sizes anywhere from CR2016 coin cells and 312 metal air cells, to AA, 32650 and D cells. We are proud of our most recent development of a prismatic cell, which is unique due to its high power drain rates. We also offer cylindrical and coin cells. Conductive materials can be incorporated into electron matrices, which are assembled into some of these cells and are tested at various current loads. We invite customers to explore opportunities of testing products in some of these battery platforms.
Coating and Doping Technology
AETC has a variety of coating and doping techniques within its arsenal of technologies. We utilize a coating of amorphous or hard carbon over spherical graphite-, silicon-, and tin- enhanced spheroidal composite materials for lithium ion batteries. Boron-doped graphites and carbons are used for oxidation-resistant applications. We also use Nano Ceramic coated electrodes and individual particles that include both anode and cathode active materials of lithium ion batteries. AETC actively works in nanotechnologies, which allows us to extract a greater capacity and improve performance at reduced particle size and lower loadings.
AETC focuses on known precious metals containing catalysts for oxygen, hydrogen, and other reactive gases. A number of our catalysts are produced from internally generated activated carbon, as well as a variety of nanomaterials which we handle in our facilities. If your application is in metal air batteries or in fuel cells, contact us to see how AETC catalytic technologies can help you.
Conductive Paints and Coatings
There is a variety of thermal, electrical, and anticorrosive coatings which AETC produces for the market of energy systems. They include specialized formulas which are designed to work at a wide range of temperatures. These coatings are engineered to withstand the corrosive environments of the battery electrolytes. Some examples include zinc-rich and anti-corrosive epoxies, glass-like graphite coatings, and nickel- and graphite-based conductive dispersions for battery can coatings. To make battery electrodes for lithium primary and lithium ion batteries, we operate a ten foot long, sophisticated, roll-to-roll battery electrode coater which allows us to produce extremely thin films on foil and mesh substrates. Our coatings’ thicknesses range from as low as one mil, 25.4 microns, to as thick as 8 mils, over 200 microns. Explore what AETC can do for you.