High Energy Density, High-Temperature Capable Multilayer Ceramic Capacitors

There is increasing interest on the development of new and inexpensive high temperature stable, high energy density dielectric materials and resultant power capacitors.  These devices can be used as a suitable replacement technology for those currently used in power conditioning and pulse power-based systems, by providing enhanced performance at higher working temperatures (> 160 °C or more).

Currently used dielectric materials only offer an energy density of ~1.2 J/cc and have seen only marginal performance gains over the past decade. During the last few years, one promising method that has been proposed to increase the energy density of power capacitors is the usage of nanocomposites that combine high breakdown strength polymers with high dielectric constant fillers, which consist of ceramic nanoparticles. Although attractive progress has been demonstrated, practical applications of the resultant capacitors are still hindered by several significant challenges, which include limited energy densities (because of the low loading of fillers) and degraded performance at high temperatures (mainly attributed to the intrinsic limitation of polymers).

On the other hand, pure ceramic capacitors, in particular multilayer ceramic capacitors (MLCCs), have attracted increasing attention because of their intrinsic high temperature capabilities. Historically, MLCCs have been excluded from large-scale applications such as pulsed power systems, because of the difficulty in firing large ceramic components with lower porosity (higher density), fewer defects, and higher mechanical reliability. However, recent progress in both dielectric materials and related processing techniques offer opportunities to address these issues, which further enable the development and fabrication of high temperature and high energy density power capacitors in a cost-effective and scalable manner.

Bioenno Power has conducted extensive R&D on high performance dielectric materials and the resultant ceramic capacitor technologies, based on novel nanostructured/nanocomposite dielectric ceramics. The objective of this development is the production of high energy density (> 2 J/cc), high temperature (> 160°C) MLCCs in a cost-effective and scalable way with commercial viability. Recent research has focused on the development of nanocomposite dielectric materials which consist of a very promising titanate-based solid solution system, and a carefully selected sintering aid component. This is a linear dielectric that is of interest for high-temperature power capacitor applications. In the meantime, this dielectric nanocomposite can be synthesized using a process that is highly compatible with conventional ceramic technology.