Fluorinated Carbamate-Based Electrolyte Enables Anion-Dominated Solid Electrolyte Interphase for Highly Reversible Li Metal Anode

Abstract

Li metal is regarded as the most promising battery anode to boost energy density. However, being faced with the hostile compatibility between the Li anode and traditional carbonate electrolyte, its large-scale industrialization has been in a distressing circumstance due to severe dendrite growth caused by unsatisfying solid electrolyte interphase (SEI). With this regard, accurate control over the composition of the SEI is urgently desired to tackle the electrochemical and mechanical instability at the electrolyte/anode interface. Herein, we report a rationally designed fluorinated carbamate-based electrolyte employing LiNO 3 as one of the main salts to induce the preferable anion decomposition to achieve a homogeneous and inorganic (LiF, Li 3 N, Li 2 O)-rich SEI. Thus, this electrolyte achieves a high Coulombic efficiency of 99% of the Li metal anode, a stable cycling over 1000 h for Li|Li symmetric cells, more than 100 cycles in 40-μm-thin Li|high-loading-NCM811 full batteries, and >50 cycles in Cu|LiFePO 4 pouch cells, which is a promising electrolyte for highly reversible Li metal batteries.

Rational Molecular Engineering via Electron Reconfiguration toward Robust Dual-Electrode/Electrolyte Interphases for High-Performance Lithium Metal Batteries

“…In comparison, the SEI formed in BCE-SN displays a uniform and thin morphology (12 nm), containing large amounts of crystalline inorganic nanoparticles with the coexistence of Li 2 O and Li 3 N (Figure b–d). Li 3 N possesses superior ionic conductivity and mechanical property, and Li 2 O plays a vital role in promoting the robustness and stability of electrode interphases. ,,− These high-quality SEI components and abundant grain boundaries can provide fast Li transport and uniform Li-ion flux for chunky lithium deposition.…”

Binary anion and cation co-doping enhance sulfide solid electrolyte performance for all-solid-state lithium batteries

“…Upon cycling, the O spectrum collected at the Li/LPS-0.05SnO 2 interface additionally shows a Li 2 O peak at 526.6 eV. The presence of Li 2 O in the interphase would modulate interfacial lithium deposition behaviors and maintain the stability of the SSE/Li interphase, thus inhibiting lithium dendrite formation within the SSE [46,47] . The initial S spectrum of LPS-0.05SnO 2 is ascribed to non-bridging sulfur Li-S-P and bridging sulfur P-S-P.…”

Constructing an inorganic-rich solid electrolyte interphase by adjusting electrolyte additives for stable Li metal anodes

“…8 An organic-dominated SEI formed through the preferential decomposition of coordination solvents cannot bear the volume expansion during Li plating/stripping cycles owing to strong bonding between the Li anode and organic SEI with low surface energy. 9 Meanwhile, the lithiophilicity of an organic SEI also drives Li vertical penetration along the Li/SEI interface to further generate Li dendrites. 10 Compared with an organic-rich SEI layer, an SEI with abundant inorganic Li compounds (such as LiF, Li 2 CO 3 , and Li 2 O) displays suitable Li + ionic conductivity, lithiophobicity, and high interfacial energy, which can promote Li transverse diffusion along the SEI/Li interface.…”