posted on 2024-01-18, 14:11authored byZhiyu Wang, Si Qin, Fangfang Chen, Shasha Chen, Dan Liu, Degang Jiang, Peng Zhang, Pablo Mota-Santiago, Dylan Hegh, Peter Lynch, Abdulrahman S. Alotabi, Gunther G. Andersson, Patrick C. Howlett, Maria Forsyth, Weiwei Lei, Joselito M. Razal
Metallic
lithium (Li) is the most attractive anode for Li batteries
because it holds the highest theoretical specific capacity (3860 mA
h g–1) and the lowest redox potential (−3.040
V vs SHE). However, the poor interface stability of the Li anode,
which is caused by the high reactivity and dendrite formation of metallic
Li upon cycling, leads to undesired electrochemical performance and
safety issues. While two-dimensional boron nitride (BN) nanosheets
have been utilized as an interfacial layer, the mechanism on how they
stabilize the Li–electrolyte interface remains elusive. Here,
we show how BN nanosheet interlayers suppress Li dendrite formation,
enhance Li ion transport kinetics, facilitate Li deposition, and reduce
electrolyte decomposition. We show through both simulation and experimental
data that the desolvation process of a solvated Li ion within the
interlayer nanochannels kinetically favors Li deposition. This process
enables long cycling stability, reduced voltage polarization, improved
interface stability, and negligible volume expansion. Their application
as an interfacial layer in symmetric cells and full cells that display
significantly improved electrochemical properties is also demonstrated.
The knowledge gained in this study provides both critical insights
and practical guidelines for designing a Li metal anode with significantly
improved performance.