A Ga–Sn liquid metal-mediated structural cathode for Li–O2 batteries

Abstract

One of the recent challenges in Li-O2 battery technology is the cycle life, which can be severely shortened by cathode passivation induced by discharge product accumulation; this can be eliminated by reducing the amount of discharge products. Herein, we report a feasibility study on the development of a Ga-Sn liquid metal (LM) functionalized multi-walled carbon nanotubes (MWNTs) cathode. In a comparison of MWNT, LM, m-LM/MWNT (pre-mixed LM and MWNTs), and LM/MWNT (LM modified MWNTs) cathodes, morphology analysis showed that small Li2O2 flakes rather than large crystals grown on the conductive Ga-Sn LM and MWNTs of the LM/MWNT cathode only. The decomposition of the flaky Li2O2 on the LM/MWNT cathode occurred at lower charge overpotentials, resulting in low polarization; thus, the cathode passivation and the consumption of the Li anode were both alleviated during the cyclic process. The LM/MWNT cathode significantly improved the cycle life, rate performance and ultimate capacity of Li-O2 batteries.

Stoichiometrically optimized eg orbital occupancy of Ni–Co oxide catalysts for Li–air batteries

“…3 Aprotic Li-air batteries (LABs) are considered the best possible alternative since they offer the highest possible theoretical energy density (11.4 kW h kg −1 ) and specific capacity (1170 A h kg −1 ). 4 A successful LAB is yet to be commercialized owing to the sluggish air cathode reaction kinetics and related parasitic reactions associated with oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) occurring during the discharging and charging steps, respectively. 5 These sluggish kinetics and parasitic reactions lead to fast decay in battery performance through an accumulation of undecomposed discharged products at the cathode surface.…”

Ga2O3 Quantum Dots with N-Doped Amorphous Carbon Fixed for Efficient Storage and Transfer of Lithium Ions by Introduction of Dopamine Hydrochloride

“…10−12 On the basis of the conversion reaction, these materials can be transformed into Ga while lithiation progresses and further combined into a Li x Ga alloy. 13 It has been proven that the transformation between the solid phase and liquid phase exists in the process of lithium and delithiation of Ga metal due to its low melting point. The cracks in the solid phase can be repaired by liquefaction.…”

“…Transition metal compound electrode materials have many advantages such as their high capacity. − As one of them, Ga-based compounds (such as GaN, Ga 2 O 3 , and Ga 2 S 3 ) are usually used in power devices, photodetectors, and other semiconductor fields. Recent studies have found that these materials usually have high capacity when used as electrode active materials. − On the basis of the conversion reaction, these materials can be transformed into Ga while lithiation progresses and further combined into a Li x Ga alloy . It has been proven that the transformation between the solid phase and liquid phase exists in the process of lithium and delithiation of Ga metal due to its low melting point.…”