Li‐containing alloys beneficial for stabilizing lithium anode: A review

Abstract

Due to the soaring growth of electric vehicles and grid-scale energy storage, high-safety and high-energy density battery storage systems are urgently needed. Lithium metal anodes, which possess the highest theoretical specific capacity (3860 mA h g −1) and the lowest electrochemical potential (−3.04 V vs standard hydrogen electrode) among anode materials, are regarded as the ultimate choice for high-energy density batteries. However, its safety problems as well as the low Coulombic efficiency during the Li plating and stripping process significantly limit the commercialization of lithium metal batteries. Recently, Li-containing alloys have demonstrated vital roles in inhibiting lithium dendrite growth, controlling interfacial reactions and enhancing the Coulombic efficiency (CE) as well as cycle life. Accordingly, in this perspective, the progresses of lithium alloys for robust, stable, and dendrite free anodes for rechargeable lithium metal batteries are summarized. The challenges and future research focus of lithium-containing alloys in lithium metal batteries are also discussed.

Germanium-Free Dense Lithium Superionic Conductor and Interface Re-Engineering for All-Solid-State Lithium Batteries against High-Voltage Cathode

“…There are various ways to prevent SE from being reduced, such as using a Li–M alloy (M = In, Mg, Sn, Zn, etc.) in place of pure lithium metal or altering the interface between lithium metal and SE using these Li–M alloys. ,− These alloy system’s primary drawbacks include high cost, significant volume expansion, poor electron insulating properties, limited theoretical capacity, slower kinetics, etc . Li–In and Li–Sn systems cost more since In and Sn are expensive metals .…”

“…Significant volume expansion also occurs in the Li–Sn alloy. Moreover, the Li–Zn alloy has a low gravimetric capacity . The kinetic behaviors are often poor in Li–Mg alloys because of the oxide layer formation over alloys .…”

Functional Fiber Materials to Smart Fiber Devices

“…296 The development of Li alloy anodes, such as M x Li (M = Si, Ge, Sn, and Al), offers promising solutions to improve the stability of the anodes. 371 A coaxial Li−air battery was developed with a lithiated Si/CNT hybrid fiber as an inner anode, a polymer gel as a middle electrolyte, and a bare CNT sheet as an outer cathode. The fiber battery showed a high energy density of 512 Wh/kg that could be effectively maintained after bending for 20 000 cycles.…”

“…Even though the gel polymer electrolyte can offer partial protection for the metal anode, the development of Li–air batteries is still challenging due to the unstable Li metal and dendrite problem, especially for the human-interfaced wearable devices . The development of Li alloy anodes, such as M x Li (M = Si, Ge, Sn, and Al), offers promising solutions to improve the stability of the anodes . A coaxial Li–air battery was developed with a lithiated Si/CNT hybrid fiber as an inner anode, a polymer gel as a middle electrolyte, and a bare CNT sheet as an outer cathode.…”

In Situ Grown MnO2 Nanoflower Arrays on Ni Foam (MnO2@NF) as 3D Lithiophilic Hosts for a Stable Lithium Metal Anode

“…With the increasing demand for battery systems with higher energy density, such as lithium sulfur batteries and lithium air batteries, the use of a lithium metal anode is now ready for a revival because of the lowest redox potential (−3.04 V vs SHE) and highest theoretical capacity (3860 mAh g –1 ). − However, the large volume change during repeated Li plating/stripping will fracture the fragile solid electrolyte interphase (SEI), which increases the Li metal surface exposure to the electrolyte, resulting in severe side reactions between Li and the electrolyte and low Coulombic efficiency (CE). − In addition, the dendrite growth resulted from heterogeneous Li deposition also easily leads to an internal short circuit, thermal runaway, and even explosion. These problems restrict the commercial application of lithium metal anode. − Up to now, several strategies, including lithium alloy, , electrolyte additives, artificial SEI films, − and solid-state electrolyte, , have been proposed to inhibit the growth of lithium dendrites and stabilize the electrode/electrolyte interface. Among these strategies, the inherent problems faced by metallic lithium anode still have not been well solved under certain service conditions.…”