A Hybrid Direct Ammonia Fuel Cell

Abstract

Ammonia has emerged as a highly promising energy carrier [1], primarily because it offers a noticeable economic benefit over hydrogen in terms of source-to-tank expenses, owing to reduced transmission, distribution, and dispensation costs [2]. Direct ammonia fuel cells (DAFCs) are capable of directly converting the chemical energy stored in ammonia into electrical energy. With its quick start-up advantage, this fuel cell technology holds great potential in the field of zero-emission transportation [3]. Although promising, this fuel cell performance needs to be much improved before the widespread commercialization becomes possible. The limiting factors include the sluggish kinetics of ammonia oxidation and the poor conductivity of anion exchange membranes. In addition, another important factor that limits the cell performance is that thermodynamically, its theoretical voltage is low (1.17 V). In this work, a hybrid direct ammonia fuel cell is developed, which consists of an alkaline anode, a cation exchange membrane, and an acid cathode. This hybrid fuel cell offers a theoretical voltage of as high as 2.55 V. The experimental results have shown that it exbibits an open-circuit voltage of 1.35 V and a peak power density of 437.1 mW cm−2 at 90 °C. Acknowledgement This work was fully supported by a grant from the National Natural Science Foundation of China (Project No. 52022003).