Sustained-Release Nanocapsules Enable Long-Lasting Stabilization of Li Anode for Practical Li-Metal Batteries

Abstract

HIGHLIGHTS • Nanocapsules made from metal-organic frameworks were designed for sustained release of additive (LiNO 3) to passivate Li anode in commercial carbonate-based electrolyte. • The nanocapsules with continuous supply of LiNO 3 formed a nitride-rich solid electrolyte interphase layer on Li anode and persistently remedied the interphase during prolonged cycling. • The practical Li-metal full cell delivered a prolonged lifespan with 90% capacity retention after 240 cycles which has been hardly achieved in commercial electrolyte. ABSTRACT A robust solid-electrolyte interphase (SEI) enabled by electrolyte additive is a promising approach to stabilize Li anode and improve Li cycling efficiency. However, the self-sacrificial nature of SEI forming additives limits their capability to stabilize Li anode for long-term cycling. Herein, we demonstrate nanocapsules made from metal-organic frameworks for sustained release of LiNO 3 as surface passivation additive in commercial carbonate-based electrolyte. The nanocapsules can offer over 10 times more LiNO 3 than the solubility of LiNO 3. Continuous supply of LiNO 3 by nanocapsules forms a nitride-rich SEI layer on Li anode and persistently remedies SEI during prolonged cycling. As a result, lifespan of thin Li anode in 50 μm, which experiences drastic volume change and repeated SEI formation during cycling, has been notably improved. By pairing with an industry-level thick LiCoO 2 cathode, practical Li-metal full cell demonstrates a remarkable capacity retention of 90% after 240 cycles, in contrast to fast capacity drop after 60 cycles in LiNO 3 saturated electrolyte.

Introducing NO3– into Carbonate‐Based Electrolytes via Covalent Organic Framework to Incubate Stable Interface for Li‐Metal Batteries

“…In sharp contrast to the morphological evolution of rod-like and needle-like Li chaotically deposited on bare Cu (Figure 2e), the Cu using COF film is deposited in smooth and dense morphology without dendrite (Figure 2f), which epitomizes the regulation of COF film on Li + deposition. Furthermore, the peaks of NO 3 at 407.6, NO 2 at 404.2, Li 3 N at 399.9, and Li x NO y at 399.0 eV [4,11,14] are detected on Cu using COF film after Li deposition process (Figure S9, Supporting Information), indicating that NO 3 decomposes to form SEI. To explore the formation mechanism of SEI, the H-type Li//Cu cell is assembled as seen in Figure 2g.…”

Constructing nitrided interfaces for stabilizing Li metal electrodes in liquid electrolytes

“…for LMBs (Figure 9b). 97 The MOF-808 has an internal diameter of 18. protective layer. The C 60 was anchored on the uneven grooves of the Li surface and resulted in a homogeneous distribution of Li + (Figure 9c).…”

Dendrite-Free and Stable Lithium Metal Battery Achieved by a Model of Stepwise Lithium Deposition and Stripping

“…The primary concern is restraining the production and growth of Li dendrites. Recent literature has yielded several effective methods such as constructing an artificial solid electrolyte interface (SEI) with high stiffness [7][8][9][10], designing functional separators [11][12][13], and modifying the electrolyte by adding additives [14][15][16] to suppress the growth of Li dendrites. Consequently, these solutions have improved the cycling stability and prolonged the lifespan of the Li metal anode.…”