High‐Performance 3D Li‐B‐C‐Al Alloy Anode and its Twofold Li Electrostripping and Plating Mechanism Revealed by Synchrotron X‐Ray Tomography

Abstract

The uncontrollable Li electrostripping and plating process that results in dendritic Li growth and huge volume change of Li anode limits the practicality of Li metal batteries (LMBs). To simultaneously address these issues, designing three‐dimensional (3D), lithiophilic and mechanically robust electrodes seems to be one of the cost‐effective strategies. Herein, a new 3D Li‐B‐C‐Al alloy anode is designed and fabricated. The prepared 3D alloy anode exhibits not only superior lithiophilicity that facilitates uniform Li nucleation and growth but also sufficient mechanical stability that maintains its structural integrity. Superior performance of the prepared 3D alloy is demonstrated through comprehensive electrochemical tests. In addition, non‐destructive and 3D synchrotron X‐ray computed tomography (SX‐CT) technique is employed to investigate the underlying working mechanisms of the prepared alloy anode. A unique twofold Li electrostripping and plating mechanism under different electrochemical cycling conditions is revealed. Lastly, improved performance of the full cells built with the 3D alloy anode and LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode corroborate its potential application capability. Overall, the current work not only showcases the superiority of the 3D alloy as potential anode material for LMBs but also provides fundamental insights into its underlying working mechanisms that may further propel its research and development.

Regulation of Li+ Diffusion via an Engineered Separator to Realize a Homogeneous Lithium Microstructure in Advanced Li-Metal Batteries

“…A Raman spectrometer (Renishaw Company, Invain, UK) and a nanoparticle potentiometer (Malvern, Malvern Zetasizer Nano ZS90, UK) were used to characterize the h-BN powder. A specially made TomoCell was assembled for in situ tomography without being separated. , X-ray CT (Rigaku Corporation CT-LAB, HX130, Japan) was used to observe the internal microstructure of the battery in an automatic mode in situ. The voltage of the X-ray tube was 70 kV, and the current was 116 μA.…”

“…A specially made TomoCell was assembled for in situ tomography without being separated. 54,55 X-ray CT (Rigaku Corporation CT-LAB, HX130, Japan) was used to observe the internal microstructure of the battery in an automatic mode in situ. The voltage of the X-ray tube was 70 kV, and the current was 116 μA.…”

In Situ Reaction Fabrication of a Mixed‐Ion/Electron‐Conducting Skeleton Toward Stable Lithium Metal Anodes

“…In order to optimize the lithium metal anodes, a series of research methods have been presented, mainly including electrolyte additives, [ 9–11 ] three‐dimensional current collectors, [ 12–17 ] construction of artificial SEI, [ 18–20 ] solid‐state electrolyte, [ 21,22 ] and separator modification. [ 23 ] Among them, three‐dimensional current collectors have been widely applied in lithium metal anodes, incorporating metal and porous carbon frameworks.…”

“…In addition, the unstable interface induces the detachment of lithium dendrites from the lithium metal surface to form 'dead Li', leading to the low Coulombic efficiency (CE) and short cycle life of lithium metal anodes. [7,8] In order to optimize the lithium metal anodes, a series of research methods have been presented, mainly including electrolyte additives, [9][10][11] three-dimensional current collectors, [12][13][14][15][16][17] construction of artificial SEI, [18][19][20] solid-state electrolyte, [21,22] and separator modification. [23] Among them, three-dimensional current collectors have been widely applied in lithium metal anodes, incorporating metal and porous carbon frameworks.…”

Elucidating the Role of Rational Separator Microstructures in Guiding Dendrite Growth and Reviving Dead Li

“…To the best of our knowledge, the mechanisms to control Li dendrite evolution can be divided into two categories: suppressing or guiding of Li growth . In the early stages of dendritic research, researchers primarily focused on suppressing dendrite nucleation and growth by changing the electrode material, − adjusting the electrolyte composition, − developing a separator, − and so forth. Among these methods, surface modification of the electrode or separator using a coating method has a significant effect on inhibiting dendrite growth. − An artificial solid electrolyte interphase can be created by coating the electrode surface with a lithiophilic material to suppress dendrite growth, which exhibits a lower electrical conductivity and higher ionic conductivity .…”