Deeply Cyclable and Ultrahigh‐Rate Lithium Metal Anodes Enabled by Coaxial Nanochamber Heterojunction on Carbon Nanofibers

Abstract

Lithium metal anodes (LMAs) are the most promising candidates for high-energy-density batteries due to the high theoretical specific capacity and lowest potential. However, the practical application of LMAs is hampered by the short lifespan and unsatisfactory lithium utilization (<50%). An oxide-oxide heterojunction enhanced with nanochamber structure design is proposed to improve lithium utilization and cycling performance of LMA under ultrahigh rates. Typically, a MnO 2 -ZnO heterojunction provides high binding energy for strong absorption of Li-ions and intimately bonded interfaces for fast transfer of electrons. Under the guidance of the smooth Li-ion migration and rapid electron flow, the Li metal can be restricted as thin layers within submicro scale in nanochambers with constrain boundary and stress dissipation, inhibiting the local agglomeration and blocking. Thus, the lithiophilic active sites can be effectively exposed to the Li-ions within submicro scale, improving the reversible conversion for high lithium utilization during long-term cycling. As such, the Li@MnZnO/CNF electrode achieves a high lithium utilization of 70% at a record-high current density of 50 mA cm −2 with areal capacity of 10 mAh cm −2 . This work offers an avenue to improve lithium utilization for long-lifespan LMAs working under high current densities and capacities.

A dendrite-suppressed and utilization-improved metallic Li anode enabled by lithiophilic nano-Pb decoration on carbon cloth

“…Obviously, our 10mg-Li@Pb@CC electrode demonstrates one of the best performance combinations in terms of overpotential and lifespan (See Table S3 † for the complete list of relevant literature data). 23,26,[41][42][43][44][45][46][47][48][49] To decipher the superiority of 10mg-Li@Pb@CC, we rst analyzed its composition and structure using XRD and XPS. As shown in ESI Fig.…”

“…Obviously, our 10mg-Li@Pb@CC electrode demonstrates one of the best performance combinations in terms of overpotential and lifespan (See Table S3† for the complete list of relevant literature data). 23,26,41–49…”

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

“…Wen et al combined 1D Cu 3 P nanowires with Cu foil as a 3D Li host, working stably over 450 h at 2 mA cm −2 /2 mAh cm −2 [ 38 ]. Yang et al [ 33 ] reported that 2D MnZnO nanosheets/CNF infused with molten Li maintained 40 h at 50 mA cm −2 and 10 mAh cm −2 . Nevertheless, the modified Li anodes with high areal capacities (> 10 mAh cm −2 ) can only be performed (< 1000 h) at limited current densities (< 10 mA cm −2 ) [ 53 – 55 ].…”

“…Inspired by selective Li nucleation/growth through heterogeneous seeds presented by Cui's group [32], various lithiophilic materials (such as oxides [33][34][35], nitrides [36,37], and phosphides [38,39]) have been embedded into carbon frameworks to reduce the overpotential of Li nucleation and regulate uniform Li nucleation/growth. Besides, some lithiophilic compounds can react with molten Li to produce Li-based compounds (like, Li 3 N, Li 2 O, and Li 3 P) and metal, which facilitates the Li-ion transfer kinetics (e.g., Li + conductivity ≈ 10 −3 S cm −1 for Li 3 N), and electron conduction [40][41][42].…”

“…Besides, some lithiophilic compounds can react with molten Li to produce Li-based compounds (like, Li 3 N, Li 2 O, and Li 3 P) and metal, which facilitates the Li-ion transfer kinetics (e.g., Li + conductivity ≈ 10 −3 S cm −1 for Li 3 N), and electron conduction [40][41][42]. Meanwhile, different morphologies of lithiophilic materials have been designed on the carbon matrix, like, zero-dimensional (0D) nanoparticles [43][44][45][46], one-dimensional (1D) nanowires [47][48][49], twodimensional (2D) nanosheets [33,50,51], etc. For example, Manthiram et al [52] prepared the 0D Mo 2 N nanoparticlesmodified carbon nanofiber (CNF) framework as a Li host, which operated over 1500 h at 6 mA cm −2 /6 mAh cm −2 .…”