Cu Current Collector with Binder‐Free Lithiophilic Nanowire Coating for High Energy Density Lithium Metal Batteries

Abstract

Despite significant efforts to fabricate high energy density (ED) lithium (Li) metal anodes, problems such as dendrite formation and the need for excess Li (leading to low N/P ratios) have hampered Li metal battery (LMB) development. Here, the use of germanium (Ge) nanowires (NWs) directly grown on copper (Cu) substrates (Cu‐Ge) to induce lithiophilicity and subsequently guide Li ions for uniform Li metal deposition/stripping during electrochemical cycling is reported. The NW morphology along with the formation of the Li15Ge4 phase promotes uniform Li‐ion flux and fast charge kinetic, resulting in the Cu‐Ge substrate demonstrating low nucleation overpotentials of 10 mV (four times lower than planar Cu) and high Columbic efficiency (CE) efficiency during Li plating/stripping. Within a full‐cell configuration, the Cu‐Ge@Li – NMC cell delivered a 63.6% weight reduction at the anode level compared to a standard graphite‐based anode, with impressive capacity retention and average CE of over 86.5% and 99.2% respectively. The Cu‐Ge anodes are also paired with high specific capacity sulfur (S) cathodes, further demonstrating the benefits of developing surface‐modified lithiophilic Cu current collectors, which can easily be integrated at the industrial scale.

High Rate and Low-Temperature Stable Lithium Metal Batteries Enabled by Lithiophilic 3D Cu-CuSn Porous Framework

“…The LFP cells tested at various rates showed that the LFP||3D Cu-LiSn-Li cell demonstrates a higher rate performance and showed a higher capacity when cycled back to 0.2 C (Figure h). The rate capacities of LFP cells with the 3D Cu-LiSn-Li anode were competitive values compared with those of other related works − (Table S2). In addition, a lower relaxation voltage can be observed from the galvanostatic curve of the LFP||3D Cu-LiSn-Li (58 mV, Figure i), compared to that of the LFP||Li (68 mV, Figure j).…”

Nucleophilic deposition behavior of metal anodes

“…66 Compared with the stable deposition process and initial sedimentation reaction, the energy required increases.Thus, for the same current density, the inducer plays an important role in the overpotential. Cu substrates, 67–69 which possess poor contact affinity with the Li metal, need the nucleation energy Δ E nuc. and are predicted to have the maximum initial deposition overpotential.…”

Advances in research on the inhibitory effect of 3D current collector structures for lithium dendrites

“…Abdul Ahad et al fabricated dense disordered germanium nanowires (Ge NWs) on copper foil using a vapor–solid–solid (VSS) method, which was then directly used as an anode current collector (Cu-Ge) for LMBs. 93 First, the cleaned copper foil was heated to 450 °C. Then, diphenylgermanane (DPG) was injected into it and cooled to obtain the composite current collector (Fig.…”