Internal short circuit (ISCr) is one of the major reasons for lithium-ion battery thermal runaway. A new phenomenon, named as the Fusing Phenomenon, is observed during the ISCr experiments. During the Fusing Phenomenon, the ISCr current path will melt down due to the Joule heat of the short current and the ISCr process will be interrupted. The Fusing Phenomenon raises the re-ISCr problem, which means that the battery may have an ISCr again after the end of the former ISCr process. The Fusing Phenomenon's life cycle is given by the hypothesis, which includes the heating-melting period, the ion discharging period and the implosion period. The heating-melting period is analyzed using an axisymmetric local ISCr model. When the ISCr area radius increases, the ISCr current path melting position will change from the ISCr area to the ISCr area edge of the aluminum current collector. If the ISCr area radius is large enough, the battery will run into the thermal runaway instead of the Fusing Phenomenon. The influence factors of the Fusing Phenomenon, including the ISCr area radius and the ISCr material, are analyzed. This research provides new insights on the battery ISCr and enriches our understanding of the ISCr process. (C) The Author(s) 2017. Published by ECS. All rights reserved.