MNTRC Newsletter Vol. 21, Issue 1: Summer 2014

Battery recovery helps keep transit sustainable

Charles Standridge, PhD, Professor and Assistant Dean

Cranford (NJ) Crossing

Layout of a disassembled lithium iron phosphate cell with an unopened cell.

GVSU News – Battery recycling is essential, as eventually all cells in all batteries will fail to hold a charge sufficient for any application. This means cleanly separating and thus recovering copper, aluminum, iron phosphate, and lithium from lithium iron phosphate batteries. Because these batteries are relatively new on the market, there are no studies about their recycling. Thus, laboratory-scale experiments were designed and conducted at Grand Valley State University’s (GVSU) School of Engineering based on a review of previous studies about lithium cobalt oxide batteries.

Acid leaching was identified as the most popular method for extracting raw materials from these batteries. Methods of disassembly are specific to each battery type due to differences in packaging, structure, and components. In this case, disassembly equipment included a glove box with fume hood and air pump, a utility knife, and a sheet metal cutter.

Four layers are contained within the jellyroll that comprises the cell beneath the outer cover. These include aluminum foil coated with lithium iron phosphate, copper foil coated with graphite, and the other two separator membranes with electrolyte residue on them. At the center of the jellyroll was a stainless steel tube.

To successfully separate the coatings from the copper and aluminum foils, we performed acid leaching using nitric acid for aluminum and sulfuric acid for copper. The experiments were conducted at various temperatures ranging from 33-60 degrees centigrade. The material was exposed to the acid for either one or two minutes. Additional validation of the recycling process will be attempted on batteries from other manufacturers.

Recycling in isolation is not economical because lithium-ion (li-ion) batteries are composed of relatively inexpensive materials. However, recycling can support closed-loop supply chains reusing materials from end-of-application batteries in the production of new batteries as well as supporting environmentalism and sustainability. Economically, the need to recycle must be supported by original, remanufacturing, and repurposing applications.

Faculty members, graduate students, and staff from GVSU’s School of Engineering are continuing research activities regarding the remanufacturing, repurposing and recycling of li-ion batteries from transit vehicles such as buses. This work is performed in partnership with Sybesma’s Electronics, a third-generation family owned business in Holland MI to insure that it has industrial applicability. The project’s overarching goal is to provide better economic value to transit operators who use electric vehicles and thus increase public transit’s sustainability.