Performance comparison for 12 V lead-carbon hybrid ultracapacitors with substrate-integrated and conventional pasted positive plates

Lead-carbon hybrid ultracapacitors comprise positive lead dioxide plates of the lead-acid battery and negative plates of carbon-based electrical double-layer capacitors (EDLCs). Accordingly, a lead-carbon hybrid ultracapacitor has the features of both the battery and that of an EDLC. In this study, the development and performance comparison between the two types of lead-carbon hybrid ultracapacitors, namely those with substrate-integrated and conventional pasted positive plates, is presented as such a study is lacking in the literature. The study suggests that the faradaic efficiencies for both types of lead-carbon hybrid ultracapacitors are comparable. However, their capacitance values as well as energy and power densities differ significantly. For substrate-integrated positive plate hybrid ultracapacitor, capacitance and energy density values are lower, but power density values are higher than pasted positive plate lead-carbon hybrid ultracapacitors due to their shorter response time. Accordingly, internal resistance values are also lower for substrate-integrated lead-carbon hybrid ultracapacitors. Both types of lead-carbon hybrid ultracapacitors exhibit good cycle life of 100,000 pulse charge-discharge cycles with only a nominal loss in their capacitance values.

A Grassmann path from AdS(3) to flat space

We show that interpreting the inverse AdS(3) radius 1/l as a Grassmann variable results in a formal map from gravity in AdS(3) to gravity in flat space. The underlying reason for this is the fact that ISO(2, 1) is the Inonu-Wigner contraction of SO(2, 2). We show how this works for the Chern-Simons actions, demonstrate how the general (Banados) solution in AdS(3) maps to the general flat space solution, and how the Killing vectors, charges and the Virasoro algebra in the Brown-Henneaux case map to the corresponding quantities in the BMS3 case. Our results straightforwardly generalize to the higher spin case: the recently constructed flat space higher spin theories emerge automatically in this approach from their AdS counterparts. We conclude with a discussion of singularity resolution in the BMS gauge as an application.