Single‐Atom Reversible Lithiophilic Sites toward Stable Lithium Anodes

Abstract

Lithiophilic sites with high binding energy to Li have shown the capability to guide uniform Li deposition, however, the irreversible reaction between Li and lithiophilic sites causes a loss of lithiophilicity. Herein, the concept of using reversible lithiophilic sites, such as single‐atoms (SAs) doped graphene, as a host, is systematically inspected in the context of Li metal battery (LMB) performance. Here, it is proposed that the binding energy to Li atoms should be within a certain threshold range, i.e., strong enough to inhibit Li dendrite growth and weak enough to avoid host structure collapse. Six kinds of SAs are utilized; doped 3D graphene, nitrogen‐doped 3D graphene, and pure 3D graphene, whose performance in LMBs are compared with each other. It is discovered that the SA‐Mn doped 3D graphene (SAMn@NG) has the most reversible lithiophilic site, in which adsorption strength with Li is suitable to guide uniform deposition and keep the structure stable. During Li plating/stripping, the changes of the atomic structures in SAMn@NG, such as change of bond length and bond angle around Mn atoms are much smaller than those on SAZr@NG, although its binding energy is higher, enabling a much‐improved battery performance in SAMn@NG. This work provides a new insight to design lithiophilic sites in LMBs.

Revisiting the Role of Physical Confinement and Chemical Regulation of 3D Hosts for Dendrite-Free Li Metal Anode

“…The voltage hysteresis of the Li-Ni/Li 3 N-NS@CC electrode (26 mV) is much smaller than that for the Li-Ni/Li 3 P-NS@CC electrode (34 mV) and Li-Ni/Li 2 O-NS@CC electrode (57 mV), which can be ascribed to the appropriate Li binding energy of Li 3 N/Ni. These results may lead to the ultra-flat deposition of Li, further inhibiting the overgrowth of SEI during the long-term cycle [ 3 , 84 ]. Overall, the Li-Ni/Li 3 N-NS@CC electrode affords the advantages of the least resistance, the highest exchange current density and the lowest Li voltage hysteresis, indicating its great potentiality as Li hosts to inhibit Li dendrite formation and improve Li metal battery performances.…”

Tannic acid assisted metal–chelate interphase toward highly stable Zn metal anodes in rechargeable aqueous zinc-ion batteries

“…EIS was employed to evaluate the charge-transfer resistance ( R ct ) of the electrode/electrolyte interface ( Figure 3A ). The TA@Zn electrode manifests a much lower R ct of 482.9 Ω than bare Zn (1,129 Ω), revealing the favorable ion transfer kinetics at the electrode/electrolyte interface, which can facilitate the fast Zn deposition ( Yang et al, 2022 ). Figure 3B shows the CV curves of the bare Zn|Ti and TA@Zn|Ti half cells.…”

Applications and Challenges of 2D Materials in Lithium Metal Batteries

“…These lithiophilic sites can not only increase the Li adsorption energy around the metal atomic sites but prevent the structural damage during the long-term cycling, thus uniform nucleation and dendrite-free deposition can be achieved (Fig. 1a) [22] . As a result, the single-atom Ni doping on nitrogen-doped graphene (SANi-NG) electrode exhibits a high average Coulombic efficiency of 98.45% over 250 cycles with a capacity of 1.0 mAh cm −2 at current density of 0.5 mA cm −2 , and a stable Li plating/stripping performance even at a high current density of 4.0 mA cm −2 .…”

“…As a result, the single-atom Ni doping on nitrogen-doped graphene (SANi-NG) electrode exhibits a high average Coulombic efficiency of 98.45% over 250 cycles with a capacity of 1.0 mAh cm −2 at current density of 0.5 mA cm −2 , and a stable Li plating/stripping performance even at a high current density of 4.0 mA cm −2 . On this basis, Yang et al further proposed the concept of reversible lithiophilic sites, where the binding energy to Li atoms should be within a certain threshold [22] . Copyright 2019, Wiley-VCH.…”

“…Fig.12D materials in LMBs. (a) Li adsorption energy distribution mappings and corresponding schematic illustrations of Li nucleation and plating process on SA metal-NG electrode[22] . Copyright 2019, Wiley-VCH.…”