Investigation of the Reversible Lithiation of an Oxide Free Aluminum Anode by a LiBH4 Solid State Electrolyte

Abstract

Abstract:In this study, we analyze and compare the physical and electrochemical properties of an all solid-state cell utilizing LiBH 4 as the electrolyte and aluminum as the active anode material. The system was characterized by galvanostatic lithiation/delithiation, cyclic voltammetry (CV), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Constant current cycling demonstrated that the aluminum anode can be reversibly lithiated over multiple cycles utilizing a solid-state electrolyte. An initial capacity of 895 mAh/g was observed and is close to the theoretical capacity of aluminum. Cyclic voltammetry of the cell was consistent with the constant current cycling data and showed that the reversible lithiation/delithiation of aluminum occurs at 0.32 V and 0.38 V (vs. Li + /Li) respectively. XRD of the aluminum anode in the initial and lithiated state clearly showed the formation of a LiAl (1:1) alloy. SEM-EDS was utilized to examine the morphological changes that occur within the electrode during cycling. This work is the first example of reversible lithiation of aluminum in a solid-state cell and further emphasizes the robust nature of the LiBH 4 electrolyte. This demonstrates the possibility of utilizing other high capacity anode materials with a LiBH 4 based solid electrolyte in all-solid-state batteries.

Lightweight complex metal hydrides for Li-, Na-, and Mg-based batteries

“…Also, after the 10th cycle, the retained capacity of the cell with the SSE electrolyte was above 3 times higher than that of the conventional counterpart. The application of LiBH 4 as SSE was reported for allsolid-state LIB with an aluminum composite anode (Al/ LiBH 4 ) [92]. The cell operated at 408 K and the C-rate of 0.1 revealed the reversible capacity of 895 mA h/g during the initial cycle, which was close to the theoretical value (993 mA h/g).…”

Functional Materials Based on Metal Hydrides

“…This work is the first example of reversible lithiation of aluminium in a solid-state cell and further emphasizes the robust nature of the LiBH 4 electrolyte. This demonstrates the possibility of utilising other high-capacity anode materials with a LiBH 4 -based solid electrolyte in all-solid-state batteries [27].…”

“…Weeks, Tinkey, Ward, Lascola, Zidan, and Teprovich [27] analyse and compare the physical and electrochemical properties of an all solid-state cell utilizing LiBH 4 as the electrolyte and aluminium as the active anode material. An initial capacity of 895 mAh/g was observed and is close to the theoretical capacity of aluminium due to the formation of a LiAl (1:1) alloy.…”

Overview of the Structure–Dynamics–Function Relationships in Borohydrides for Use as Solid-State Electrolytes in Battery Applications

“…More useful insights are gained when additionally using characterization techniques that measure structure and dynamics. Lithium ion conductivity LiBH 4 is 10 −3 S/cm in the high temperature hexagonal phase [15]. To examine the stability of the hexagonal phase at temperatures lower than 130 • C, we used Raman spectroscopy to track the structural changes in the BH 4 − unit with temperature on ramp up and ramp down at a slow heating and cooling rate of 5 • C/min (Figure 6).…”