Compared to Li-ion batteries, metal-air batteries show the higher energy densities [
1-
3], demonstrating great potential for energy storage systems [
4-
8]. Rechargeable lithium-oxygen (Li-O
2) batteries have attracted wide attention due to high theoretical energy density (3500 Wh/kg) that originates from the reversible reaction of lithium peroxide [
9-
12]. Traditionally, Li-O
2 cells are composed of the Li anode, separator and cathode catalyst [
13-
20]. According to different electrolytes, batteries can be divided into four categories: non-aqueous, aqueous, hybrid, all-solid-state electrolytes [
18,
21-
24]. A non-aqueous Li-O
2 battery includes a lithium foil anode, a cathode electrode and the nonaqueous electrolytes, where the lithium salts are dissolved in nonaqueous electrolyte. For aprotic Li-O
2 cells, Li is oxidized to Li
+ during discharge process, while O
2 is dissolved in the solvent to react with Li
+ and generate Li
2O
2 [
24-
29]. For the charge process, the insulating Li
2O
2 is decomposed to generate Li
+ and O
2 [
30-
32]. However, the porous cathodes are seriously passivated by the insulating discharge products (Li
2O
2). To address the passivation issues, the Li-O
2 batteries with aqueous the electrolytes are proposed [
33]. Different from the non-aqueous Li-O
2 batteries, the discharge product of aqueous Li-O
2 batteries is LiOH, which can enhance the conductivities of discharge products, thereby promoting the electrochemical performances. To inhibit the direct contact between the lithium anode and the aqueous electrolytes, a hybrid non-aqueous/aqueous system is further proposed, which can improve the stability and durability of Li-O
2 batteries [
34]. Actually, the aforementioned non-aqueous, aqueous and hybrid electrolytes are based on the liquid solvents which can cause the safety issues and result in low energy densities. To improve the safety and energy densities, a variety of solid-state solvents containing polymers and inorganic solid electrolyte are utilized in Li-O
2 batteries [
35]. Though different kinds of Li-O
2 batteries show huger potential than that of Li-ion batteries, the commercialization of Li-O
2 cells is always impeded by various barriers including low energy efficiency, inferior cycle performances and unavoidable side reactions from electrolytes and cathodes [
36-
39]. Especially, the high charge overpotentials caused by the insulated Li
2O
2 can cause the degradation of solvents and electrodes, and therefore leading to poor performances [
40-
46]. To alleviate the high charge overpotentials, various catalysts such as carbon materials [
46-
52], transition metal oxides [
53-
61], perovskites [
37,
62-
65] and noble metals [
66-
69] are utilized to accelerate the oxidation of Li
2O
2. Among the cathode catalysts, due to half-filled antibonding states, noble metal-based catalysts are regarded as a promising catalysts for Li-O
2 batteries, which can tune adsorption strength towards intermediates [
70]. However, the charge mechanism of Li-O
2 cells with noble metals has not been elucidated clearly. For instance, Byon
et al. revealed that noble metal could simultaneously facilitate the oxidation of solvents and discharge products [
30]. Therefore, the cycle performance cannot be obviously enhanced. In comparison, Kang
et al. proposed that the anisotropic Pt would facilitate the generation and oxidation of Li
2O
2, delivering enhanced OER catalytic activities compared to commercial Pt/C catalysts [
71]. Therefore, a comprehensive understanding of the oxidation mechanism is essential to rationally design efficient noble metal catalysts for promoting the oxidation of discharge products at low charge overpotentials.