Integrated Hybrid Fuel Cell-Battery Power Generator Enabled through Electrochemical Hydrolysis of Nanoporous Aluminum

Abstract

Over the past decade, tremendous progress has been made in transitioning from fossil fuel-based transportation to electric vehicles powered either by lithium-ion battery (LIB) or proton-exchange membrane (PEM) fuel cell technologies. A hybrid fuel cell-battery power generation system is more attractive than a battery alone, or a fuel cell alone, since a battery is able to meet the high-power requirements during peak demands (e.g. acceleration), while a fuel cell can be used as a range extender. Existing hybrid PEM fuel cell-battery power generation systems consist of separate LIB and PEM fuel cell systems that are coupled together. In this configuration, the hydrogen used to feed the PEM fuel cell is stored on-board in high-pressure tank.In this talk, I will present our novel integrated hybrid PEM fuel cell-battery power generation system, which can simultaneously produce both electricity, acting as a battery, and hydrogen gas, which is then used to directly feed a PEM fuel cell, from a single device. We have previously reported the scalable synthesis of novel bulk nearly oxide-free nanoporous aluminum (NP-Al) and the ability to produce hydrogen gas through “chemical” hydrolysis of NP-Al in pure water, with solid aluminum hydroxide, hydrogen gas and heat as the only reaction products. [1] The new hybrid power system proposed here builds on this work through the introduction of a novel cell configuration which facilitates the spontaneous “electrochemical” hydrolysis of NP-Al, during which aluminum is oxidized at the anode, electrons from this oxidation reaction diffuse through an external circuit to the cathode where hydrogen evolution takes place, meanwhile electricity is also generated from electrons flowing through the external circuit. This electricity is the equivalent of the heat generated during chemical hydrolysis reaction, meaning that during electrochemical hydrolysis, the only reaction products in case of 100 % reaction efficiency are solid aluminum hydroxide, hydrogen gas and electricity without heat. In this talk, I will discuss this novel cell, current progress and outlook for future development. Reference: [1] Corsi JS, Fu J, Wang Z, Lee T, Ng AK, Detsi E. (2019). Hierarchical Bulk Nanoporous Aluminum for On-Site Generation of Hydrogen by Hydrolysis in Pure Water and Combustion of Solid Fuels. ACS Sustainable Chemistry and Engineering, 7, 11194–11204. doi.org/10.1021/acssuschemeng.9b00481