Modeling and Simulation of All-Solid-State Batteries with Block Copolymers

Kurzfassung

All-solid-state batteries (ASSB) are experiencing a growing scientific interest in recent years as potential next-generation high-voltage batteries with great intrinsic safety. Using polymer electrolytes in ASSBs can solve problems with current battery technologies, such as dendrite growth [1] and flammability [2]. Particularly with regard to mechanical properties and stability, polymers are promising compared to other solid electrolytes. A large number of different polymers are currently being discussed [3]. In this contribution, we investigate the processes in block copolymer electrolytes [2] by a multi-physics continuum transport model. The methodological framework for thermodynamically consistent modeling is given in previous work of Latz et al. [4]. The description of the polymer electrolyte material is based on the specific free energy, which includes contributions due to mechanics, configuration and polarization. For the configurational free energy, the Flory-Huggins solution model is applied to catch the entropic behaviour of a polymer solution. In contrast to transport theories of other electrolytes, we formulate our model with respect to the polymer velocity. This enables us to parameterize the model with data from simulations on the atomic scale, e.g. from molecular dynamics simulations [5]. We investigate the behavior of ASSBs with polymer electrolytes under different operating conditions and compare our simulations to experiments as well as simulations of other types of electrolytes. The most prominent differences are expected for the configurational and mechanical properties. This is a first step towards the theory-based spatially and time-resolved description of processes in ASSBs with block copolymer electrolytes.