Amorphous MOF as smart artificial solid/electrolyte interphase for highly-stable Zn-ion batteries

Ion transport and conduction in metal–organic framework glasses

“…The Zr-based MOF was applied as a coating to protect the Zn anode of a Zn-ion battery. 15 The articial SEI layer offered several benets that ultimately led to a long cycling life of 1800 h for the battery at a current density of 1 mA cm −2 , which include: (1) dangling bonds (-PO 3 H − or -PO 3 2−…”

“…) that provided Zn 2+ hopping sites for migration and electrostatic shielding of anions in the electrolyte to inhibit side reactions, (2) pores that sieve pure Zn 2+ for deposition and (3) isotropic conduction pathways that lead to smooth dendrite-free Zn deposition. 15 It is speculated that the implementation of MOF glass through melt-quenching may further eliminate any potential discontinuities in the articial SEI layer.…”

“…The Zr-based MOF was applied as a coating to protect the Zn anode of a Zn-ion battery. 15 The artificial SEI layer offered several benefits that ultimately led to a long cycling life of 1800 h for the battery at a current density of 1 mA cm −2 , which include: (1) dangling bonds (–PO 3 H − or –PO 3 2− ) that provided Zn 2+ hopping sites for migration and electrostatic shielding of anions in the electrolyte to inhibit side reactions, (2) pores that sieve pure Zn 2+ for deposition and (3) isotropic conduction pathways that lead to smooth dendrite-free Zn deposition. 15 It is speculated that the implementation of MOF glass through melt-quenching may further eliminate any potential discontinuities in the artificial SEI layer.…”

“…This leads to a homogeneous migration of ions, which suppresses the formation of dendrites and improves the cycling stability in batteries. 14,15 Additional benefits are offered by MOF glass, which include the formation of bulk material with no grain boundaries and high moldability. 16–18 The lack of grain boundaries is favourable for fast ion conduction as the activation energy for ions traversing across grain boundaries is usually significantly higher than the bulk material.…”

In situ defect engineering in a multifunctional layer with strong zincophilicity and high Zn-ion conductivity on Zn anodes

“…Most recently, increasing efforts have been made to construct ex situ or in situ solid electrolyte interphase (SEI) layers on Zn anodes to separate Zn from solvated water and regulate Zn 2+ electroplating chemistry. 28,29 However, the ex situ SEI layers still face some problems in their manufacture and application, such as a tedious formation process, poor stability and poor compatibility between the electrode and electrolyte. Compared with ex situ SEI layers, the in situ SEI layers can be naturally formed on Zn anodes with good compatibility and electrochemical stability, but the composition and thickness of the electrolyte-derived SEI layers are not controllable.…”