Kinetically Stable Oxide Overlayers on Mo3P Nanoparticles Enabling Lithium–Air Batteries with Low Overpotentials and Long Cycle Life. Issue 50 (9th November 2020)

• Record Type: Journal Article
• Authors: Kondori, Alireza; Jiang, Zhen; Esmaeilirad, Mohammadreza; Tamadoni Saray, Mahmoud; Kakekhani, Arvin; Kucuk, Kamil; Navarro Munoz Delgado, Pablo; Maghsoudipour, Sadaf; Hayes, John; Johnson, Christopher S.; Segre, Carlo U.; Shahbazian‐Yassar, Reza; Rappe, Andrew M.; Asadi, Mohammad
• Is Part Of: Advanced materials. Volume 32:Issue 50(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-11-09
• Subjects: lithium–air batteries -- lithium–oxygen batteries -- non‐aqueous electrolytes -- oxygen evolution reaction -- transition metal phosphides; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202004028
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: The main drawbacks of today's state‐of‐the‐art lithium–air (Li–air) batteries are their low energy efficiency and limited cycle life due to the lack of earth‐abundant cathode catalysts that can drive both oxygen reduction and evolution reactions (ORR and OER) at high rates at thermodynamic potentials. Here, inexpensive trimolybdenum phosphide (Mo3 P) nanoparticles with an exceptional activity—ORR and OER current densities of 7.21 and 6.85 mA cm −2 at 2.0 and 4.2 V versus Li/Li +, respectively—in an oxygen‐saturated non‐aqueous electrolyte are reported. The Tafel plots indicate remarkably low charge transfer resistance—Tafel slopes of 35 and 38 mV dec −1 for ORR and OER, respectively—resulting in the lowest ORR overpotential of 4.0 mV and OER overpotential of 5.1 mV reported to date. Using this catalyst, a Li–air battery cell with low discharge and charge overpotentials of 80 and 270 mV, respectively, and high energy efficiency of 90.2% in the first cycle is demonstrated. A long cycle life of 1200 is also achieved for this cell. Density functional theory calculations of ORR and OER on Mo3 P (110) reveal that an oxide overlayer formed on the surface gives rise to the observed high ORR and OER electrocatalytic activity and small discharge/charge overpotentials. Abstract : Mo3 P nanoparticles with a kinetically stable oxide overlayer exhibit remarkable ORR/OER activities near thermodynamic potentials in non‐aqueous media. Using this catalyst alongside TEMPO and DBBQ redox mediators in a lithium–air battery favors the solution‐based mechanism for epitaxial growth of Li2 O2 at the lowest overpotentials, the effects of which are addressed through directed experimental efforts in electrochemical characterization coupled with a computational approach.