A New Cathode Material for a Li–O₂ Battery Based on Lithium Superoxide

Abstract

Li–O2 batteries suffer from large charge overpotentials due to the high charge transfer resistance of Li2O2 discharge products. A potential solution to this problem is the development of LiO2-based batteries that possess low charge overpotentials due to the lower charge transfer resistance of LiO2. In this report, IrLi nanoparticles were synthesized and implemented for the first time as a LiO2 battery cathode material. The IrLi nanoparticle synthesis was achieved by a temperature- and time-optimized thermal reaction between a precise ratio of iridium nanoparticles and lithium metal. Li–O2 batteries employing the IrLi-rGO cathodes were cycled up to 100 cycles at moderate current densities with sustained low cell charge potentials (<3.5 V). Various characterization techniques, including SEM, DEMS, TEM, Raman, and titration, were used to demonstrate the LiO2 discharge product and the absence of Li2O2. On the basis of first-principles calculations, it was concluded that the formation of crystalline LiO2 can be stabilized by epitaxial growth on the (111) facets of IrLi nanoparticles present on the cathode surface. These findings demonstrate that, in addition to the previously studied Ir3Li intermetallic, the IrLi intermetallic also provides a means by which LiO2 discharge products can be stabilized and confirms the importance of templating for the formation process.

Reversible Discharge Products in Li–Air Batteries

“…[100] Besides the Ir 3 Li intermetallic, [21,101] Curtiss et al recently synthesized IrLi nanoparticles and it enabled the formation of LiO 2 in Li-O 2 batteries. [102] The DFT analysis illustrated the lattice matching of LiO 2 (111) with the ( 111) and (110) facets of IrLi; thus, the LiO 2 was favorable to grow on the IrLi surface. Sun et al proposed a new sealed battery that cycled by interconversion of the reversible LiO 2 and Li 2 O 2 .…”

“…recently synthesized IrLi nanoparticles and it enabled the formation of LiO 2 in Li–O 2 batteries. [ 102 ] The DFT analysis illustrated the lattice matching of LiO 2 (111) with the (111) and (110) facets of IrLi; thus, the LiO 2 was favorable to grow on the IrLi surface. Sun et al.…”

Sabatier Relations in Electrocatalysts Based on High‐entropy Alloys with Wide‐distributed d‐band Centers for Li‐O2 Batteries

“…To prompt an enhancement, various catalysts have been developed, such as metal oxides, [2] metal sulfides, [3] noble metals, [4] single-atom catalysts, [5] and alloys. [6] However, a practical design guidance for high-performance catalysts is still absent.…”

Heterogeneous Catalyst as a Functional Substrate Governing the Shape of Electrochemical Precipitates in Oxygen-Fueled Rechargeable Batteries

“…Herein, we revisited the role of functional catalytic substrates regulating the nucleation and growth of Li 2 O 2 . ,− Catalyst-mediated growth of Li 2 O 2 has been limited in adsorption/binding energy and lattice mismatch so far. , The controlled solid/solid interface from metal/oxide to Li 2 O 2 /electrode is achieved by detouring heterogeneous nucleation with a lower energy barrier. The hexagonal surface-oxygen rings on cuprite (Cu 2 O) promote homogeneous Pd distribution, which acts as a nucleation seed for further electrochemical precipitation of Li 2 O 2 .…”

“…16,33−35 Catalystmediated growth of Li 2 O 2 has been limited in adsorption/ binding energy and lattice mismatch so far. 29,36 The controlled solid/solid interface from metal/oxide to Li 2 O 2 /electrode is achieved by detouring heterogeneous nucleation with a lower energy barrier. The hexagonal surface-oxygen rings on cuprite 1a).…”