U.S. Coal to Conductive Inks

The United States coal industry has experienced diminishing production becauseof increased utilization of natural gas and renewable energysources for electric power production. This has resulted in a significant loss of jobs within the coal mining industry and the related coalfired power generation sectors of the U.S. economy. Because of the adverse impacts on our economy and society, the U.S. Department of Energy initiated a program to develop alternative uses of coal for other than combustion for electric power generation. As part of this DOE sponsored program, Minus 100 was awarded an SBIR Grant and has been developing processes for the production of electrically conductive pigments, suspensions and inks for use in the electrical printed circuit markets. To assist in the development of said technology, Minus 100 has been collaborating witha major graphite supplier, several ink formulators and a commercial electronic circuit printer.In 2018 Minus 100 LLC was awarded a Phase I Grant entitled “U.S. Coal to Conductive Inks.” Minus 100 was able to produce coalbased conductive ink pigments/inks that had printed electrical sheet resistivities of ≤ 1000 ohm/sq/mil. Products in this resistivity range are suitable for selected dissipative and resistive electrical applications. In 2018, Minus 100 was awarded a Phase II Grant and further enhanced theelectrical resistivity of the conductive pigments/inks produced to ≤ 100 ohm/sq/mil. In this electrical resistivity range, the coalbased products are suitable for selected thermal heating applications. Because of the COVID Pandemic, Minus 100 and its collaborators were not able to complete all of the work that wasplanned for Phase II.Therefore, acontinuation of the Phase II research is proposed for a Phase IIA Project. The objective of an “all carbon pigment/ink will be to achieve a printed ink sheet resistivity of ≤ 10 ohm/sq/mill. With hybrid metal/coalbased pigments, the objective will be to achieve a printed sheet resistivity of ≤1 ohm/sq/mil. At these printed ink sheet resistivity levels, a significant number of printed circuit applications and electrode applications are available. The conductive ink market in2020was about $3.0 billion US and is expected to grow to $3.7 billion by 2025 at a CAGR of 4.1%. The primary enduse applications are in the printing of photovoltaic components, radio frequency identification antennae, printed circuit boards, membrane switches, displays, battery electrodes and thermal heating elements. The initial commercialization target will be supplying the ink for selected heating element applications.