A new method to improve the efficiency of liquid metal batteries based on magnetohydrodynamic instability analysis

Recently, liquid metal batteries (LMBs) as a potentially cheap grid scale energy storage are investigated popularly again. At present, the reason, why LMBs still cannot be promoted widely and commercialized, is that, the LMBs are susceptible to various kinds of instabilities, which may trigger fast irregularly liquid metal flow and imply a risk of short circuit of LMBs. In this paper, we propose a new structure, called grid-structure (GS), which is helpful to suppress the magnetohydrodynamic (MHD) instabilities in LMBs and hence to improve the charging/ discharging efficiency. The critical applied electric potential (AEPcr), is introduced to represent the threshold value, above which the MHD instabilities will set in. The numerical investigations verify that the specially inserted GS can change both distributions of flow field and toroidal induced magnetic field, hence to improve the AEPcr and suppress the MHD instabilities of LMBs. The GS is of great significance to the promotion of the gridscale LMBs.