Tailoring deposition and morphology of discharge products towards high-rate and long-life lithium-oxygen batteries

Abstract

Lithium-oxygen batteries are an attractive technology for electrical energy storage because of their exceptionally high-energy density; however, battery applications still suffer from low rate capability, poor cycle stability and a shortage of stable electrolytes. Here we report design and synthesis of a free-standing honeycomb-like palladium-modified hollow spherical carbon deposited onto carbon paper, as a cathode for a lithium-oxygen battery. The battery is capable of operation with high-rate (5,900 mAh g À 1 at a current density of 1.5 A g À 1 ) and long-term (100 cycles at a current density of 300 mA g À 1 and a specific capacity limit of 1,000 mAh g À 1 ). These properties are explained by the tailored deposition and morphology of the discharge products as well as the alleviated electrolyte decomposition compared with the conventional carbon cathodes. The encouraging performance also offers hope to design more advanced cathode architectures for lithium-oxygen batteries.

Realizing the Embedded Growth of Large Li2O2 Aggregations by Matching Different Metal Oxides for High‐Capacity and High‐Rate Lithium Oxygen Batteries

“…For α‐MnO 2 , the first ORR step was proven to be a Li + adsorption process with desolvation (Equation (S1) in Figure S8 of the Supporting information),31, 32, 49 obtaining an electron and further adsorbing O 2 to form LiO 2 * (“*” represents adsorbed species) at the MnO 2 surface (Equation (S2) in Figure S8 of the Supporting information) 50, 51. Then, LiO 2 * transforms to Li 2 O 2 through an electrochemical reduction or a disproportionation reaction (Equation (S3) in Figure S8 of the Supporting information) 50, 52.…”

Verifying the Rechargeability of Li‐CO2 Batteries on Working Cathodes of Ni Nanoparticles Highly Dispersed on N‐Doped Graphene

“…Through the TEM screening, amorphous C covers the Ni‐NG cathode like a film, and Li 2 CO 3 prefers to gather together into particles around Ni. More importantly, the unique highly dispersed porous structure with Li 2 CO 3 particles and large film‐like amorphous C ensures uniform electrolyte distribution around the discharge products, and then enhances the decomposition of the products during the charge and results in an improvement in the reversibility 31, 32, 33…”

“…As revealed by high‐resolution narrow X‐ray photoelectron spectroscopy (XPS) of Li1s, the peak of Li 2 CO 3 at 55.4 eV decreases obviously after the subsequent charge process, and only the residual signal can still be distinguished (Figure S11, Supporting Information), consistent with SAED. Even so, the superior cyclic stability indicates that massive active sites on Ni‐NG could contribute to the homogenous distribution of Li 2 CO 3 and C, and are beneficial to retain the porous structure after electrochemical processes 27, 32…”

A Bifunctional Organic Redox Catalyst for Rechargeable Lithium–Oxygen Batteries with Enhanced Performances

“…Therefore, catalysts have been utilized to reduce the overpotentials and to increase the cycle life. Potential catalysts such as metals, metal oxides, perovskite, carbon nanotubes, graphene, and organic compounds have been investigated 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24. Ruthenium metal has recently demonstrated superior capability to reduce charge overpotential during the oxygen evolution reaction (OER) over other catalysts 25.…”