Navitas Systems’ Advanced Solutions Group (ASG) Research and Development team brings considerable knowhow in lithium ion cell and battery research, development, engineering and manufacturing, totaling hundreds of years of combined experience. So when we interact with a customer about their problems and needs, this brainpower engenders confidence that our recommendations, proposals, programs and products are grounded in fundamentals. See Below the wide ranging examples of our cell development work.
High Power Cells
One of the core competencies of Navitas ASG’s cell R&D team is the development of high power cells. Several team members were key contributors to the development of A123 Systems’ AHR18700M1 Formula 1 racing cell, as well as to the development of later generations of the cell. This expertise served the ASG site well during later cell development projects, and two notable high power cells were developed for U.S. Government applications.
Small format prismatic nanophosphate cell
A small format, high power cell was developed and validated in bench-level testing. The cell chemistry was based on the AHR18700M1 chemistry, but further optimized for greater energy and power density, and packaged in a soft pouch-type prismatic package.
Large format prismatic metal oxide cell
A large format mid-to-high power prismatic cell is currently in development at Navitas ASG. This cell features metal oxide chemistry, and is engineered for a balance of mid-to-high power along with moderate energy density. It is presently optimized for high power operation in low-temperature environments—a difficult operating regime for lithium-ion chemistry cells and a main driver of the cell’s overall high power design.
Prismatic pouch and custom metal can cells
In addition to specifically high power cells, Navitas ASG has developed a variety of custom lithium-ion cells. More than ten custom lithium-ion cells have been designed and prototyped. Due to the high packaging and high packing efficiencies of prismatic cells, Navitas ASG has concentrated on prismatic cell design of both pouch-type cells and cells packaged in custom metal cans. The capacities of our cell portfolio range between 22mAh (a small, extremely thin metal can cell) and 45Ah (a large size metal can cell) with most cells in the 2 to 12Ah range. Cell chemistries have ranged from standard or custom nanophosphate to advanced custom metal oxide chemistries featuring extremely high energy density (600 Wh/L).
Infrastructure as impressive as the people
Navitas ASG’s 20,000-square-foot Ann Arbor, Michigan facility houses world class materials science, cell testing, pilot scale electrode coating capabilities, a 720-square-foot dry room, wet lab, prototype assembly, machine shop and a hardened cell test facility. Furthermore, Navitas offers additional manufacturing and testing capabilities at its state-of-the-art facility in Woodridge, Illinois.
A partial list of the available research equipment follows:
Lab scale materials production
Jar, attritor, and jet mills, controlled-atmosphere tube furnaces up to 6 inches in diameter, and drying ovens. Small mixers and K Coater for producing small electrodes for both coin cells and SLP’s (single layer pouch cells).
High resolution field emission SEM with EDAX, cross section preparation tools including ion polishing and mechanical polishing capability, DTA-TGA thermal analysis, micropore analysis (Hg porosimetry) , rheometry, viscometry, KF and Vapor Pro water content analysis systems (can perform this on electrodes, electrolytes and slurries) and Keyence light microscope (100x to 5kx) capable of performing optical profilimetry and a Keyence Image Dimension Measurement System.
Electrode and cell fabrication
Semi-automated small format prismatic cell assembly line in a Scientific Climate Systems Inc. (SCSI) 720 square foot dry room (maximum 2 percent relative humidity), Toyo/MEGTEC slot die electrode coating machine with both IR and convection drying capability, Ross PDDM-2 slurry mixers, IRM Model 200 heated-roll calendaring press, Hohsen Type 2520 coin cell press, three glove boxes, spot and ultrasonic welders, and vacuum drying ovens.
Pilot scale coating and cell assembly
The pilot facilities are a near exact copy of that used in high volume production which has been qualified by commercial customers.
The Navitas Systems Advanced Products Group features a semi-automated cell development and production facility, featuring a pilot coater and cell assembly equipment. This production facility is tooled and staffed to produce a variety of small to large format prismatic cells. This equipment is operated in a 720 square foot dry room. The facility assures a highly reproducible assembly process. This eliminates noise associated with cell assembly to assure that any differences in performance can be attributed to the intended variables in our experimental designs. Because this facility has been built around state of the art cell production equipment, it offers an excellent foundation for establishing a pilot or limited volume production capability.
Over 400 Maccor automated test channels (up to 35V, 240A), Solartron and EG&G potentiostats for EIS, CV and other electrochemical test methods, and multiple environmental chambers (-70 to 200°C). These test channels and environmental chambers support electrochemical performance evaluation using commercially relevant prototype cells and test protocols.