(Invited) Alternative Battery Failure Initiation Methods

Propagating battery failure, where the energetic failure of a single cell leads to a cascading thermal runaway of other cells within a battery system, is of increasing concern as battery systems become larger and include greater numbers of cells. However, testing cell to cell propagation requires a method for initiating or simulating single cell runaway while adding a minimum of excess energy into the system. Traditionally single cell failure is initiated with standard battery abuse tests, such as overcharge, thermal ramp and nail penetration tests. However, nail penetration tests can be difficult to perform in fully developed battery systems while overcharge and thermal ramp add a significant amount of excess energy into the battery system. Recent work at Sandia has looked at non-traditional thermal runaway triggers that can be applied to off-the-shelf cells. Heat generation from a single cell was determined through accelerating rate calorimetry (ARC) and used to determine the total flux needed from high power quartz lamps to simulate the thermal runaway of a nearby cell. This was then used to initiate single cells with radiative heating. Single cells were also initiated using a fiber coupled laser to create a localized failure on a cell. This was evaluated for multiple laser energy levels and cell orientations, and coupled with CT evaluation of the point of failure. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.