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A flexible polymer-based Li–air battery using a reduced graphene oxide/Li composite anode

Guo, Ziyang, Li, Jinli, Xia, Yuan, Chen, Chao, Wang, Fengmei, Tamirat, Andebet Gedamu, Wang, Yonggang, Xia, Yongyao, Wang, Lei, Feng, Shouhua
Journal of materials chemistry 2018 v.6 no.14 pp. 6022-6032
additives, air, anodes, batteries, deformation, electric potential difference, electrolytes, electronics, energy density, gels, graphene oxide, mass density, polymers, protective effect, relative humidity, silica, volatilization
Flexible Li–air batteries have been proposed as a potential power source for next-generation flexible electronics due to their super-high theoretical energy density. However, the safety problems derived from dendritic-deposition and high-activity of a Li anode and the leakage and volatilization of liquid electrolyte severely impede their practical application. Herein, we design a flexible belt-shaped Li–air battery with high stability and safety, which is constructed by using a reduced graphene oxide (rGO)/Li anode, gel polymer electrolyte containing LiI and 4 wt% SiO₂ (4% SiO₂–LiI-GPE). The rGO/Li anode shows lower mass density, better toughness and less dendrite growth compared with a pure Li anode. Additionally, 4% SiO₂–LiI-GPE has a high ionic conductivity of 1.01 mS cm⁻¹, flame-resistant polymer matrix, excellent protective effect on the Li anode and no-leakage properties. Furthermore, the synergy of the LiI and SiO₂ additives promotes the decomposition of discharge products and improves the safety of the battery at the same time. As a result, this belt-shaped Li–air battery can steadily run for 100 cycles with a small average overpotential of ∼1.45 V in ambient air (relative humidity of 15%) under different mechanical deformations. Moreover, its voltage curves over operation could remain almost unchanged under a series of bending conditions.