Understanding the low temperature electrochemistry of magnesium-lithium hybrid ion battery in all-phenyl-complex solutions

Muhammad Rashad,Muhammad Asif

doi:10.1016/j.jechem.2020.08.018

Abstract

Magnesium–lithium hybrid ion batteries have emerged as a new class of energy storage systems owing to dendrite free cycling of magnesium anode and possibility of practice of numerous conventional lithium cathodes. In present work, we used hybrid ion strategy to analyze the performance of lithium titanate based lithium cathode, magnesium metal anode, and all-phenyl complex (APC) electrolytes at different temperatures (25 °C, 10 °C, 0 °C, −10 °C, and −20 °C). The hybrid ion battery exhibited excellent rate performance (228 mAh g−1/20 mA g−1 and 163 mAh g−1/1000 mA g−1) with stable voltage plateaus at 0.90 and 0.75 V, which corresponds to specific energy of 178 Wh kg−1 at room temperature (25 °C). Experimental results revealed that APC-THF solutions have strong potential to suppress the freezing of electrolyte solutions owing to low boiling point of THF. The low temperature electrochemical testing revealed the reversible capacities of 213.4, 165.5, 143.8, 133.2 and 78.56 mAh g−1 at 25, 10, 0, −10, and −20 °C, respectively. Furthermore, ex-situ XRD, SEM, and EIS tests were carried out to understand the reaction kinetics of both Mg2+ and Li+ ions inside the lithium titanate cathode. We hope this work will shed light on low temperature prospective of electrochemical devices for use in cold environments.

Highlights

Among various energy storage devices, rechargeable metal ion batteries have attracted tremendous research attraction in past few decades owing to their high consumption in electronic, automobiles and electric vehicle industries [1,2,3,4]
To overcome the problem of energy storage at low temperatures, a strategy was successfully explored in terms of magnesium-lithium hybrid ion system and magnesium metal anode
The ionic conductivity of all-phenyl complex (APC) electrolyte was enhanced by introducing the lithium salt

Summary

Introduction

Among various energy storage devices, rechargeable metal ion batteries have attracted tremendous research attraction in past few decades owing to their high consumption in electronic, automobiles and electric vehicle industries [1,2,3,4]. Extensive research was carried out to elaborate the capabilities of magnesium ion batteries with Ni0.75Fe0.25Se2 [7], CuS nano-particles [8], NiS2 [9], TiO2-B nanowires [10], Bi-rGO nanocomposites [11], and C-Ti2S4 [12] cathodes etc. Their performance is still far from practical needs, mainly because of sluggish magnesium ion transportations inside cathodes. The working mechanism of Li4Ti5O12 spheres in APC-LiClTHF electrolytes was examined by ex-situ XRD, EIS and SEM, and by analyzing the electrochemical impedance spectroscopy and cyclic voltammetry as low temperatures

Experimental

Results and discussion

Conclusions