To address the issue of high energy storage costs in integrated energy systems (IES) and further refine the relationship between energy storage and carbon emissions, this paper focuses on retired electric vehicle batteries. It constructs a model that integrates a second-life battery energy storage system (SLBESS) into an IES to achieve low-carbon economic dispatch. Firstly, the paper establishes a charge-discharge power model for retired electric vehicle batteries. Based on this model, it further constructs an SLBESS model within the IES to fully utilize the residual value of retired batteries. Secondly, the paper traces the carbon flow distribution of the SLBESS and establishes a full life cycle carbon emission model. An economic benefit analysis of this model is conducted to evaluate its advantages in both economic and environmental aspects. Finally, a day-ahead rolling dispatch model for the IES incorporating the SLBESS is established and solved using the Model Predictive Control (MPC) method. This approach ensures the rationality of the dispatch plan and the low-carbon economic operation of the system, providing a feasible low-carbon solution for integrated energy systems. In summary, by constructing and analyzing the application model of the SLBESS in the IES, this paper not only offers new insights into addressing high energy storage costs but also contributes to achieving low-carbon economic dispatch.