Nail penetration, safety tests

Na-S system/battery 571,574 nail penetration, safety tests 354 naphthalene 428... 

Underwriters Laboratories (UL) requires that consumer batteries pass a number of safety tests (UL 1642 [119] and UL-2054 [120]). There are similar recommendations from UN for transport of dangerous goods, [121] the International Electrotechnical Commission (lEC), and the Japan Battery Association [122]. An abnormal increase in ceU temperature can occur from internal heating caused by either electrical abuse - overcharge or short circuit - or mechanical abuse - nail penetration or crush. Higher ceU temperature could also be a result of external... 

Ichimura M (2007) The safety characteristics of lithium-ion batteries for mobile phones and the nail penetration test. In Proceedings of the 29th international telecommimications energy... 

Nail penetration [27,28,32,34,35]. An internal cell short can be simulated by this test and all cells need to pass it, because there is no safety device to prevent it. In this test, a nail of adequate diameter (e.g. 2.5 mm) is forced into the battery at a prescribed speed, followed by a hard current flow at the pass point, thereby generating the joule heat violently. Smoke and fire can be observed, concomitantiy with the voltage and temperature monitoring. The worst case occurs when the cell internal resistance is the contact resistance of the short point. 

Due to their reactivity with electrolyte solutions, especially in the charged state, the most useful thermal behavior testing (e.g., DSC) of the candidate cathode materials occurs in the presence of electrolyte. Below, the results of a comprehensive study done by MacNeil et al. [9] have been used in preparation of graphs shown in Figs. 5.4, 5.5, 5.6, and 5.7, with several cathode/electrolyte system behavior trends identified and discussed common cathode name abbreviations used in the discussion are listed in Table 5.1. Similar studies are commonly done by the lithium-ion battery manufacturers on various cathode and/or electrolyte materials candidates and are usually treated as a basic introduction to the ARC testing and other safety-related experiments on larger cells (overcharge, nail penetration tests, etc.). 

An attractive feature of C/LiMn204 polymer Li-ion cells is their ability to sustain abuse. Safety and abuse tests passed by C/LiMn204 polymer Li-ion cells are listed in Table 35.25. In addition, C/LiMn204 polymer Li-ion cells can sustain nail penetration in the fully charged state or the overcharged state without explosion or Are. 

Several safety tests for batteries have been described (96). In the nail penetration test, a LiCo02/mesocarbon microbeads full battery with the branched oligomer showed a significant improvement in the thermal stability and was able to restrain the temperature of the battery at about 85°C. The nail penetration test was conducted according to the standard procedure described in UL1642 (97) and SBA GllOl (98). An internal short circuit occurs upon nail penetration, and the thermal runaway behavior can be observed if there is no mechanism to quench the heat or stop the chain reaction quickly. 

Video of nail penetration, which was performed to investigate the safety behavior of a cell under penetration of a strong nail into the cell, is shown in the results section of this article. Prior to the test, the cell was fully-charged at a rate of C/6. Once the desired state of charge was reached, the cell was carefully placed and safely fastened on to a specially designed stand. The thermocouple was placed behind the cell, which makes it not visible in the attached video. During the nail penetration test, the cell was perforated with nail and the position of the nail was... 

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