Reduced Graphene Oxide-Polypyrrole Composite as a Catalyst for Oxygen Electrode of High Rate Rechargeable Li-O₂Cells

Abstract

Polypyrrole (PPY) is grown on reduced graphene oxide (RGO) and the composite is studied as a catalyst for O 2 electrode in Li-O 2 cells. PPY is uniformly distributed on the two dimensional RGO layers. Li-O 2 cells assembled in a non-aqueous electrolyte using RGO-PPY catalyst exhibit an initial discharge capacity as high as 3358 mAh g −1 (3.94 mAh cm −2 ) at a current density of 0.3 mA cm −2 . The voltage gap between the charge and discharge curves is less for Li-O 2 (RGO-PPY) cell in comparison with Li-O 2 (RGO) cell. The Li-O 2 (RGO-PPY) cell delivers a discharge capacity of 550 mAh g −1 (0.43 mAh cm −2 ) at a current density of 1.0 mA cm −2 . The results suggest that RGO-PPY is a promising catalyst of O 2 electrode for high rate rechargeable Li-O 2 cells.

Nanofibrous Co3O4/PPy Hybrid with Synergistic Effect as Bifunctional Catalyst for Lithium‐Oxygen Batteries

“…Their electrodes with TPPy‐supported electrolytic manganese dioxide catalyst showed improved reversible capacity of nearly 2000 mAh g −1 , higher round‐trip efficiency, and especially superior rate capability compared with conventional carbon supported cathodes. Composites of PPy grown uniformly on reduced graphene oxide were also studied by Munichandraiah and co‐workers as catalysts for Li‐O 2 batteries, and a discharge capacity of 3353 mAh g −1 was delivered . Although the reversible formation and decomposition of Li 2 O 2 product was detected during the discharge/recharge process in the work of Wen's group, no systematic investigation of the intrinsic discharge/recharge products or the stability during cycling of pristine PPy has been reported.…”

Characteristics of discharge products in all-solid-state Li-air batteries

“…In particular, the high polarizations of the oxygen reduction (ORR) and oxygen evolution reactions (OER) are the most serious problem that impedes applications such as electric vehicles and electricity storage, because the large change in cell voltage for the charge and discharge processes results in low energy storage efficiency. To reduce these polarizations, various investigative approaches such as fundamental analyses on the ORR and OER [8], catalysts for ORR and OER [9,10], carbon air electrode [11], and the 3 rd electrode for OER [12] have been reported. However, electrode polarization at high current density has not been significantly improved.…”

Electrochemical Properties of RuO2 Catalyst for Air Electrode of Lithium Air Battery

“…Figure 12 shows Raman spectra for the discharged air electrodes loaded with the RuO 2 (10 wt%)/KB in the three kinds of electrolyte solutions of 1mol/l LiTFSA/PC, TEGDME and DMSO. The peak positions were referred from previous reports (9,16). No discharge products were observed for TEGDME-and PCbased solutions.…”

“…Various kinds of oxygen reduction/evolution electrocatalyst materials or support materials (6,7,11,12,16) have been intensively investigated with a view to improving such electrochemical properties of air batteries as their cycleability and Q RTE value. Thus far, mainly transition metal-based oxides and macrocyclic complex compounds such as MnO 2 (2,4,5,9,17), Mn-Fe-based mixed oxides (6,13) and Co phthalocyanine (1,3) have been examined as electrocatalysts.…”

“…Conventionally-used carbonate esters such as propylene carbonate (PC) are reported to be unstable toward the oxygen radical anions (17). Recently, novel solvents such as tetraethylene glycol dimethyl ether (TEGDME) (12,16) and dimethyl sulfoxide (DMSO) (11,14,15) have been used to prevent electrolyte decomposition.…”