Regulated Li Electrodeposition Behavior through Mesoporous Silica Thin Film in Anode-Free Lithium Metal Batteries

Abstract

Lithium metal anode material suffers from the formation of a dendritic structure and manufacturing difficulties in Li metal batteries. Although anode-free lithium metal batteries (AFLMBs) have received broad interest due to their high energy density and easy fabrication, controlling the morphology of electrodeposited Li is challenging. In this work, we report on the use of mesoporous silica thin films (MSTFs) with perpendicular nanochannel (pore size ∼6 nm) stacking on a stainless steel (SS) substrate as the MSTF⊥SS for advancing AFLMBs. The MSTF⊥SS substrate with inorganic structures improves the stability of the Li plating/stripping process in Li-MSTF⊥SS cells at a current density of 2 mA cm −2 and capacity of 2 mAh cm −2 . A LiFePO 4 cathode (mass loading: ∼12 mg cm −2 ) paired with the MSTF⊥SS electrode delivered an initial discharge capacity of 154 mA h g −1 , which is ∼20% higher than that of the bare SS electrode at a C rate of 0.1C. Grazing-incidence wide-angle X-ray scattering results suggest that MSTF regulates the Li electrodeposition process with individual microcrystals and leads to the formation of Li(110). Also, the electrodeposited Li film with a uniform surface is obtained on the MSTF⊥SS substrate. The designed porous MSTF with high stability, ultrasmall pore size, and lithiophilic properties enhances the performance of AFLMBs with the LiFePO 4 cathode during 100 cycles.

A chemical lithiation induced Li4.4Sn lithiophilic layer for anode-free lithium metal batteries

“…The accumulation of dead Li causes rapid capacity fade of the cell. 18 Thus, many different strategies have been developed to improve the uniformity of lithium deposition on heterogeneous substrates in AFLMBs, where all the active lithium is provided by the cathode, including electrolyte additives, 11,[19][20][21][22][23][24] surface modication of the current collector, [25][26][27][28][29][30] and articial SEI. [31][32][33] Among them, one effective approach is to increase the surface lithiophilicity of the copper current collector by uniformly constructing a lithiophilic layer, which provides abundant nucleation sites by enhancing the affinity of lithium.…”

Modulating the Voltage Decay and Cationic Redox Kinetics of Li‐Rich Cathodes via Controlling the Local Electronic Structure

“…A home‐built online GC system (Agilent 7890) with a pulsed discharge helium ionization detector was used to analyze the gas products. [ 56,57 ] Since each GC measurement required 30 min, the released gases were accumulated in the cell for 30 min during the charge–discharge process prior to the GC measurements.…”

Anode‐Free Solid‐State Lithium Batteries: A Review

“…Similarly, Lo et al reported the use of mesoporous silica thin films (MSTF) with vertical nanochannels stacked on stainless steel (SS) substrates to improve the battery performance. [104] The MSTF composite layer consists of a continuous mesoporous silica film, ≈30 nm thick, possessing negatively charged uniform perpendicular nanochannels (6.5 ± 0.3 nm), which makes it electrically insulating and has good lithium affinity. The porous MSTF regulates the lithium electrodeposition process by the microcrystalline structure, allowing lithium deposition on the Li (110) surface with the activation energy of only 0.01 eV, which is even lower than the LiAg alloy.…”

“…d) Schematic illustrations of the Li electrodeposition process on the SS and MSTF⊥SS in the anode-free Li metal batteries. Reproduced with permission [104]. Copyright 2021, American Chemical Society.…”