Instrumentation for Battery Research
Abstract
Abstract publicly releasable. POC Lynn Petersen Program Officer ONR 331Lithium ion cells are well suited for a wide range of applica,e types of lithium ion cells especially lithium iron phosphate and lithium titanate can provide service life of thousands of cycles., When Lithium ion cells are combined into modules which are further combined into battery strings, additional challenges arise which, affect lifetime and reliability. A research program is currently underway at MIT, investigating properties of lithium ion cells, wi,th emphasis on useful life of such cells under stressful operation. This proposal is for equipment that will expand the range of vol,tage and current for cycle testing a Navy energy magazine module and therefore the size of cell arrays up to 12S 18P with nominal 39,V 45 Ah capacity operated at up to 10C rate. At present the experiments, which take significant time, are limited by available equip,ment. The purpose of the proposed equipment is to support experimental research that will enable more rapid development of improved, power electronic modules for faster, higher power density cycle testing to support development of cell and battery models while pro,viding students with experience related to low voltage power electronic module development and advanced battery evaluation. We are d,eveloping high current capability low ESR charge shuttling cell voltage balancers and bidirectional DC to DC converter modules for h,igh round trip efficiency cycle testers. Multiple high power density regenerative power supplies could be used to cycle test and emu,late battery cells and modules for development and evaluation of cell voltage balancer and cycle testing power electronic to facilit,ate improved cell and battery module cycle testing and modeling. We have developed a cell characterization procedure including on th,e order of a few hundred cycles to quantify cell behavior and are developing a three capacitor equivalent RC circuit model. This inc,ludes parameters as a function of test conditions including SOC, current and temperature to emulate complex and interactive effects, on the performance of lithium ion cells and battery modules under a range of operating conditions. Our test procedures include cell, characteristic measurements such as capacity fade in each 20 cycle test set to provide cycle life projections under a significant n,umber such as 15 sets of conditions. A Hioki BT4560 battery impedance meter is used for cell impedance measurement at various freque,nce parameters and the open circuit voltage vs SOC. Analysis of cycle test data combined with Impedance test and OCV analysis result,s is used to find the remaining Long time constant impedance parameters. This procedure will be used to explore the limits of a numb,er of candidate cells for use by the Navy in pulsed power and reserve power applications. Additional experimental systems will be us,ed to evaluate a wider variety of cells and/or run full cycle , coordination with colleagues at Temple University who are modeling and evaluating the behavior of lithium ion cells while mechanica,lly stressing cells. The MIT team can run electrical evaluation of cells at up to maximum operating conditions and exceeding some sp,ecifications to explore the operating envelope and to develop methods of possibly detecting damaged cells. The lab equipment will he,lp us to improve our test facility to provide data to help enable the US Navy and other military organizations to select suitable ce,lls, to design energy storage systems for pulsed power and reserve applications and to maintain batteries in service.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 16, 2022
- Source ID
- N000142212326
Entities
People
- James Kirtley
Organizations
- Massachusetts Institute of Technology
- Office of Naval Research
- United States Navy