Tackling realistic Li+ flux for high-energy lithium metal batteries

Abstract

Electrolyte engineering advances Li metal batteries (LMBs) with high Coulombic efficiency (CE) by constructing LiF-rich solid electrolyte interphase (SEI). However, the low conductivity of LiF disturbs Li+ diffusion across SEI, thus inducing Li+ transfer-driven dendritic deposition. In this work, we establish a mechanistic model to decipher how the SEI affects Li plating in high-fluorine electrolytes. The presented theory depicts a linear correlation between the capacity loss and current density to identify the slope k (determined by Li+ mobility of SEI components) as an indicator for describing the homogeneity of Li+ flux across SEI, while the intercept dictates the maximum CE that electrolytes can achieve. This model inspires the design of an efficient electrolyte that generates dual-halide SEI to homogenize Li+ distribution and Li deposition. The model-driven protocol offers a promising energetic analysis to evaluate the compatibility of electrolytes to Li anode, thus guiding the design of promising electrolytes for LMBs.

Promoting Surface Electric Conductivity for High‐Rate LiCoO2

“…In addtion, time-of-flight secondary-ion mass spectrometry (ToF-SIMS) demonstratres (Figure S18), LCO-M1 has a more uniform cathode electrolyte interphase (CEI) layer mainly composited with LiF 2 À and other inorganic species. [14] It should be related to the higher surface electric conductivity, [15] and could effectively suppresses side reactions and lattice oxygen loss, confirmed by differential electrochemical mass spectrometry (DEMS) (Figure S19).…”

Fast Polysulfide Conversion Catalysis and Reversible Anode Operation by A Single Cathode Modifier in Li‐Metal Anode‐Free Lithium‐Sulfur Batteries

“…Electrochemical impedance spectroscopy (EIS) was carried out on Li ∥ SEI/Li cells which paired the recovered anodes with Li metal. The size of the semi‐ellipses in the EIS plots can be used to represent Li + mobility resistance (Rs) in the SEI [38] . Figure S7b shows that the Li ∥ SEI/Li cell using a recovered In 2 Se 3 @CNT‐Li 2 S ∥ Cu anode has a smaller Rs than that of the cell using a recovered CNT‐Li 2 S ∥ Cu anode.…”

“…The size of the semi-ellipses in the EIS plots can be used to represent Li + mobility resistance (Rs) in the SEI. [38] Figure S7b shows that the Li k SEI/Li cell using a recovered In 2 Se 3 @CNT-Li 2 S k Cu anode has a smaller Rs than that of the cell using a recovered CNT-Li 2 S k Cu anode. Hence the presence of the LiInS 2 /LiInSe 2 components in the SEI enabled Li + to move with higher mobility in the SEI.…”

Strategies and challenges of carbon materials in the practical applications of lithium metal anode: a review

“…26 Nevertheless, especially in the last decade, the application of Sand's time has been extrapolated to all electrolytes under investigation, including solid-state (polymer) electrolytes and liquid non-aqueous electrolytes, which can certainty no longer satisfy the original constraint on when Sand's time was derived. 49,50 Now, Sand's time model is still widely employed to describe the time of the initial nucleation process for Li dendrites, 51 implying that the larger local current areal density is an important factor causing dendrites. 52,53 Carbon host materials mainly include graphite (natural graphite and artificial graphite), low-dimensional carbon materials (such as graphene and carbon nanotubes), and amorphous carbon obtained by the carbonization of organic precursors.…”