Key Aspects of Lithium Metal Anodes for Lithium Metal Batteries

Abstract

Rechargeable batteries are considered promising replacements for environmentally hazardous fossil fuel‐based energy technologies. High‐energy lithium‐metal batteries have received tremendous attention for use in portable electronic devices and electric vehicles. However, the low Coulombic efficiency, short life cycle, huge volume expansion, uncontrolled dendrite growth, and endless interfacial reactions of the metallic lithium anode are major obstacles in their commercialization. Extensive research efforts have been devoted to address these issues and significant progress has been made by tuning electrolyte chemistry, designing electrode frameworks, discovering nanotechnology‐based solutions, etc. This Review aims to provide a conceptual understanding of the current issues involved in using a lithium metal anode and to unveil its electrochemistry. The most recent advancements in lithium metal battery technology are outlined and suggestions for future research to develop a safe and stable lithium anode are presented.

Lithium Metal Interface Modification for High‐Energy Batteries: Approaches and Characterization

“…Li is an extremely reactive metal as it quickly loses an electron due to a shielding effect of the nucleus and then forms Li À ions, which are highly reactive and thermodynamically unstable. [23,66] Thus, in batteries, Li metal tends to spontaneously react with most atmospheric gases, electrolyte solvents, and salts, with or without a current flow. In addition, the flow of current during battery operation is irregularly localized on the surface of Li metal anodes, resulting in several severe problems, such as the formation of an unstable SEI layer, massive volume expansion, and unpredictable untoward reactions with electrolytes.…”

“…[3,[19][20][21] Recently, various research groups have been devoting all of their efforts into understanding Li metal anode mechanisms and upgrading Li metal anodes by trying out new methods. [2,16,[22][23] First, porous host structures have been used to reduce the local current density on the electrode surface to accommodate volume expansion and to prevent dendritic Li growth using strategies involving 3D carbon [24][25][26][27][28][29] and 3D inactive metal structures. [30][31][32][33][34][35] Second, another useful solution is to develop a new electrolyte system.…”

Silicon Quantum Dots Induce Uniform Lithium Plating in a Sandwiched Metal Anode

“…However, the development of Li metal anodes lags far behind conventional cathodes because of the non‐ideal Li deposition. A favorable Li deposition at the anode/separator interface increases the risk of short circuits caused by the dendrite penetration through separator . Non‐ideal Li deposition induces irregular superficial layer of solid electrode interphase (SEI), which may repeatedly consume cyclable Li atoms during charge/discharge and lower the Coulombic efficiency (CE).…”

“…Non‐ideal Li deposition induces irregular superficial layer of solid electrode interphase (SEI), which may repeatedly consume cyclable Li atoms during charge/discharge and lower the Coulombic efficiency (CE). Therefore, developing high‐efficiency Li metal anodes is of vital importance to increase the specific energy of Li‐based batteries …”

“…They have been coated on the surface of some scaffolds or porous carbon to facilitate Li deposition. Lithiophilic coating strategies have demonstrated continuous and considerable success in the development of Li metal anodes . In the past, these lithiophilic materials were usually used as a conventional anode to reversibly store Li above 0 V vs. Li/Li + .…”