Series multilayer internal electrodes for high energy density glass-ceramic capacitors

The glass-ceramic dielectrics and internal electrode structures are investigated for improving the general energy storage density of capacitors. Calculation indicates that glass-ceramics acquired from glass matrix annealing at 850°C for 3 hours can be approximately up to 17 J/cm³ in energy storage density. They are appropriately chosen as the dielectrics for preparing high energy storage density capacitors (HESDCs). A series multilayer structure of internal electrode is developed for the HESDCs, in which each layer is a combination of gold film and silver paste. This electrode structure promises the capacitor immune from the residual porosity defects inevitably brought by electrode paste sintering process, and specifically improves the electrical breakdown strength of the capacitor. Based on this new electrode structure, the energy storage densities of capacitors are increased by more than one order of magnitude compared with those traditional ones with only single layer of internal electrode. Thus, HESDCs based on the optimized glass-ceramic dielectrics can potentially achieve 7.5 J/cm³ in energy storage density, even taking into consideration the enlargement of total capacitor volumes while encapsulating practicable capacitors from dielectrics media.