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Lithium batteries have a tendency to fail violently under adverse conditions leading to the rapid venting of gas. Overcharge, thermal heating, and a combination of the two conditions are applied here to investigate the gas venting process. A test chamber has been constructed with data recordings including chamber pressure and temperature, battery voltage, current, and surface temperature as functions of time throughout the charging and failure processes. High-speed imaging and schlieren flow visualization are used to visualize the gas venting process. A direct comparison between lithium iron phosphate based K2 26650 and lithium nickel manganese cobalt oxide LG 18650 cells is made through a test series of the three failure methods. Failure under thermal, overcharge, and thermal-overcharge conditions are generally similar in terms of the gas venting process, but are observed to have increasingly energetic failures. The thermal-overcharge abuse condition demonstrates an ability to reconnect via internal short circuit even after an initial electrical failure seen as the refusal to accept charge. This reconnection is associated with a secondary, more energetic failure which can produce weak shock pressure waves.

Rats were implanted with an indwelling vascular cannula in the jugular vein, femoral artery or carotid artery, and evaluated for postsurgical weight changes and cannula patency. Complete details for surgical methods and materials are presented for each procedure. Over a 14 day period, the carotid artery procedure produced the most profound weight loss, while the jugular vein implantation was followed by minimal changes in body weight. Weight loss was intermediate for the femoral artery group. Body weight had returned to, or was above presurgical weight at 2, 4 and 6 days postsurgery for the jugular, femoral and carotid catheterizations, respectively. By 14 days following implantation 83%, 67% and 50% of the femoral, carotid and jugular cannulas, respectively, were patent. We conclude that for long-term sampling of blood in the rat, the femoral artery catheterization procedure is preferable in terms of patency and postsurgical weight loss.