Fire and explosion safety research on space purposed Li-ion accumulators
Аuthors1*, 2**, 2***, 2****
2. Keldysh Research Centre, 8, Onezhskaya str., Moscow, 125438, Russia
Fire and explosion safety experimental investigations of Russian space applicated prismatic lithium — ion accumulators are carried out in SSC Keldysh Research Centre. The main aim of this study was the test of lithium — ion accumulators for ignition and explosion resistance in the case of external short circuit and shock generated by metal punch.
The first step before the main tests for external short circuit is to charge the lithium — ion accumulators by direct current until the achievement of 4,2 V voltage at the terminals. During the short circuit carrying out the accumulator terminals were bridged by copper conductor with resistance ~ 100 mOm.
The tests for ignition and explosion resistance in the case of external short circuit and shock generated by metal punch were carried out with the help of special device with impact energy up to 120 J, which is sufficient for piercing of accumulators 60 mm in thickness (the thickness of the steel case is 0,6 mm).
Experimental results of external short circuit tests have shown that the charged prismatic accumulators in predeformed and non predeformed conditions were heated up (up to 150 °C), however maintaining deformation and destruction didn’t happen, and, as a result of it, there is no noticeable influence on the surrounding equipment.
During the investigations for ignition and explosion resistance the critical test of lithium-nickel-cobalt-oxidic electrochemical system led to impossibility of further accumulator operating. As a result of this test there was an internal short circuit after penetration of metal punch in the charged accumulator. Internal short circuit of the accumulator led to heating up (more than 500 °C), destruction of a safety membrane and welded seams, exit of the evaporated electrolyte and electrodes material. Destruction has explosive character and makes essential impact on the surrounding equipment (high temperature of the construction, a stream of hot gas).
Keywords:short circuit, the lithium-ion battery, reliability, fire and explosion safety, temperature control
- Kedrinski I.A., Jakovlev V.G. Litii-ionnye akkumulators (Ion-lithium accumulators), Krasnojarsk, Planeta, 2002, 266 p.