In the case of a traffic accident, it must be possible to disconnect lithium-ion batteries independently and safely from electrical consumers. At present, mechanical relay switches are used, but these cause noise. For electric cars in particular, the requirements for noise emission of components are becoming more stringent. A semiconductor-based isolating switch can be used as an alternative for this application. The solution presented in this article offers advantages in terms of high current capability, excellent thermal properties (continuous and transient) and long service life, while at the same time being cost-effective, since the power electronics are largely made of a pure aluminium alloy.