Authors: P.J. Schubert, A. Urbanek
Affilation: IUPUI, United States
Pages: 418 - 422
Keywords: hydrogen storage porous silicon gaseous recharge
Porous silicon as a storage media can store up to 7.1% hydrogen by weight [1,3]. The round-trip energy difference is 1.2 kJ/mol, but the as-synthesized energy barrier requires 410 C for complete thermal discharge . Barrier height reduction is possible via strategically-placed catalyst deposition, facilitating the spillover effect [3,4,5]. The temperature for thermal discharge of hydrogen can be modulated via catalyst loading . Recharging with molecular hydrogen from a gaseous state is governed by surface diffusion [7,8]. This work presents new results of recharge time as a function of temperature and pressure. Balance of system designs are developed for two use-case scenarios, the “slow home” recharge (8 hours) and the “fast fleet” recharge (3.5 minutes). In each case, the vessel , fittings, and control electronics are included to allow computation of system-level storage metrics for hydrogen. These are compared against DOE system goals  for evaluation as viable candidates for the commercial marketplace. Preliminary estimates for cost have been made for the “slow home” configuration which yield $7.73 per kWhr media costs (a factor of 20 lower than Li-ion batteries) and 5.8% storage by weight.