Confronting the Challenges in Lithium Anodes for Lithium Metal Batteries

Abstract

With the low redox potential of −3.04 V (vs SHE) and ultrahigh theoretical capacity of 3862 mAh g −1 , lithium metal has been considered as promising anode material. However, lithium metal battery has ever suffered a trough in the past few decades due to its safety issues. Over the years, the limited energy density of the lithium-ion battery cannot meet the growing demands of the advanced energy storage devices. Therefore, lithium metal anodes receive renewed attention, which have the potential to achieve high-energy batteries. In this review, the history of the lithium anode is reviewed first. Then the failure mechanism of the lithium anode is analyzed, including dendrite, dead lithium, corrosion, and volume expansion of the lithium anode. Further, the strategies to alleviate the lithium anode issues in recent years are discussed emphatically. Eventually, remaining challenges of these strategies and possible research directions of lithium-anode modification are presented to inspire innovation of lithium anode.

Rigid and Flexible SEI Layer Formed Over a Cross‐Linked Polymer for Enhanced Ultrathin Li Metal Anode Performance

“…However, the batteries using Cu foil grafted with C‐1 polymer could run for over 1300 h. Nevertheless, the polarization voltage of the bare Cu foil sharply increased to 100 mV after 1300 h, indicating that an unstable SEI layer not only led to the generation of dendrites and dead Li during battery cycling but also an increased Li + transportation impedance. [ 16 ] Similarly, as shown in Figure 3d, when the tests were operated at an increased current density of 2 mA cm −2 with a cycling capacity of 1 mAh cm −2 , the same trend is observed wherein the batteries with C‐2 grafted skin could work for more than 2000 h, while the bare Cu foil could only last for 180 h. The batteries using the C‐2‐modified Cu foil could also show a stable cycling for 1300 h at a higher current density of 3 mA cm −2 (Figure 3e). The battery performance was also tested at a current density of 1 mA cm −2 (Figure S15, Supporting Information).…”

“…[9][10][11] Different strategies for modulating the Li anode interface were investigated, including the use of electrolyte additives and artificial SEI layers. [12][13][14][15][16][17][18] Among them, regulating the composition of the SEI layers by changing the solvation structure of Li + using electrolyte additives seemed simpler. [19] During the transfer of Li + through the SEI layer, Li + desolvation causes coordination anions and solvents to decompose and spontaneously form the SEI layer.…”

Sandwich-like solid composite electrolytes employed as bifunctional separators for safe lithium metal batteries with excellent cycling performance

“…1–3 However, the conventional LMBs using ordinary polyolefin separators and a high content of liquid electrolyte based on esters or ethers always suffer from the risk of fire on account of the high flammability, 4,5 and the cycle lifetime reduction ascribed to the uncontrollable lithium dendrite growth caused by heterogeneous lithium deposition. 6–8 In this context, on the one hand, lots of efforts for safe LMBs commonly focus on exploring fire-prevention systems by introducing a fire retardant into electrolytes, 9,10 modifying separators with inorganic particles, 11,12 designing thermoresponsive switch membranes and so on. 13–15 On the other hand, the studies aspiring to achieve long cycling properties pay close attention to fresh strategies of electrolyte/electrode interface engineering for dendrite-free lithium anodes, such as in situ formation of an artificial SEI film, 16–18 construction of three-dimensional lithium matrices, 19 preparation of high-strength composite separators as mechanical barriers, 20,21 and interfacial redistribution of ions across the separators or at the lithium metal surface.…”

3D Correlative Imaging of Lithium Ion Concentration in a Vertically Oriented Electrode Microstructure with a Density Gradient

“…Rechargeable Li ion batteries (LIBs) are the current battery of choice with rapidly increasing demands from electrified transport and electricity storage from intermittent renewable sources. [1][2][3] Inside a LIB, Li + ions are extracted from the cathode active material, diffused in a liquid electrolyte through the cathode porous structure to the anode, and inserted into the anode active material during charging, and the process is reversed during discharging. [4][5][6] A key process in determining battery performance is Li + ion diffusion in the pores of electrodes and insertion in the electrode active materials.…”