High Rate and Stable Solid-State Lithium Metal Batteries Enabled by Electronic and Ionic Mixed Conducting Network Interlayers

Abstract

All solid-state lithium (Li) metal batteries (SSLMBs) are attractive for prospective electrochemical energy storage systems on account of their high energy densities and good safeties. However, the incompatible interface between the solidstate electrolyte and Li metal anode limits the ability of SSLMBs. Here, a threedimensional (3D) electronic and ionic mixed conducting interlayer is proposed to improve the interfacial affinity in SSLMBs. The 3D electronic and ionic mixed conducting interlayer is composed of a Sn/Ni alloy layer-coated Cu nanowire (Cu@ SnNi) network. The Li plating demonstrates that the Cu@SnNi network can possess fast Li + ion transport channels from the Li metal to LiFePO 4 , acting as a stable interlayer between the Li metal and solid polymer electrolyte. Noticeably, the solidstate LiFePO 4 /Li cell with a Cu@SnNi interlayer exhibits an excellent rate capability (133 mA h g −1 , 2 C; 100 mA h g −1 , 5 C) in comparison to the low rate performance of the cell without the interlayer (117 mA h g −1 , 2 C; 60 mA h g −1 , 5 C). This unique structure design of electronic and ionic mixed conducting interlayer provides an alternative strategy to improve the performance of SSLMBs.

Three-Dimensional Magnesiophilic Scaffolds for Reduced Passivation toward High-Rate Mg Metal Anodes in a Noncorrosive Electrolyte

“…The 3D Mg 3 Bi 2 cell shows the lowest E nu of 0.014 V, whereas the 3D Cu cell shows a larger E nu of 0.13 V. The difference can be attributed to the better Mg affinity of the Mg 3 Bi 2 alloy. ,, Mg 3 Bi 2 is magnesiophilic because of its binding interactions with Mg, , thus rendering a uniform deposition (Figure d,e). The lithium alloy-type scaffolds, such as Li 15 Si 4 , , LiSn, , and LiAl, have proven their advantage in low nucleation barriers for lithium metal. Note that copper, unlike bismuth, cannot be alloyed with Mg (Figure S9).…”

“…32,33,41 Mg 3 Bi 2 is magnesiophilic because of its binding interactions with Mg, 33,43 thus rendering a uniform deposition (Figure 2d,e). The lithium alloy-type scaffolds, such as Li 15 Si 4 , 42,43 LiSn, 44,45 and LiAl, 33 have proven their advantage in low nucleation barriers for lithium metal. Note that copper, unlike bismuth, cannot be alloyed with Mg (Figure S9).…”

Porous Lithiophilic Li–Si Alloy‐Type Interfacial Framework via Self‐Discharge Mechanism for Stable Lithium Metal Anode with Superior Rate

“…[ 19a ] The electronic conductivity of LSIF@Li was ≈8.0 × 10 –2 S cm –1 and comparable to that of bare Li (≈1.3 × 10 –1 S cm –1 ), which ensures rapid transfer of electrons in interfacial LSIF. [ 40 ] Hence, as a mixed ion and electron conducting scaffold, LSIF is expected to play a significant role in regulating Li + depletion and electric field distribution near the anode surface and in improving Li + mobility and rate capability of LMB simultaneously. [ 41 ]…”

Porous Mixed Ionic Electronic Conductor Interlayers for Solid-State Batteries

“…For example, Yang et al [23] cycled Li-Mg random-solid-solution alloy, which has an appreciable solubility of Li atoms and thus can be considered as a MIEC, and reported stable cycling over a few hundred cycles at a high current density of ≥~1 mA cm -2 . Furthermore, Zhu et al [24] utilized a Sn-Ni alloy-coated Cu nanowire network as an anode (Figure 3(b)), where Li-Sn intermetallic compound forms upon lithiation and functions as a MIEC. They demonstrated a notable improvement in rate capability-a doubling of capacity at 5C and a more than five times increase in cycle life at 1C as compared to the Li metal anode-without detrimental corrosion or stress-induced collapse.…”

“…Second, porous MIECs can secure electronconducting paths even when there exists electron-insulating debris spalled off from the SE/β-phase interface as they conduct electrons in a redundantly percolating fashion. As the rate at which R ct increases upon cycling can be slowed down in 3D porous MIEC-assisted SSBs, better rate capability can be anticipated [22][23][24].…”