Intercalation (chemistry)

Electrochemistry

Materials science

Chromatography

Cathode

Solvent

Inorganic chemistry

Diglyme

Physical chemistry

Organic chemistry

Analytical Chemistry (journal)

Crystallography

Chemistry

Electrode

Anode

Electrolyte

ACS Energy Letters

We report on layered Na2Ti3O7/MgNaTi3O7/Mg0.5NaTi3O7 nanoribbons for reversible electrochemical Mg storage. First, Mg2+ intercalation with irreversible Na+ deintercalation takes place in the first discharge process (Na2Ti3O7 + Mg2+ + e– → MgNaTi3O7 + Na+). Then, reversible Mg2+ insertion–extraction occurs in subsequent cycling processes (MgNaTi3O7 ↔ Mg0.5NaTi3O7 + 0.5Mg2+ + e–). This reaction with repeatable 0.5 M Mg2+ occupying the sites of Na+ coordinated to seven oxygen atoms offers a theoretical capacity of 88 mA h g–1 (78 mA h g–1 in practical test with Mg2+ electrolyte). Furthermore, the MgNaTi3O7 was used to assemble full Mg-ion batteries (MIBs) with Mg(ClO4)2–diglyme electrolyte and V2O5 cathode. The cell delivers a reversible capacity of 75 mA h g–1 corresponding to an energy density of 53 Wh kg–1. This work displays the potential of layered Na2Ti3O7/MgNaTi3O7/Mg0.5NaTi3O7 as the anode of MIBs.

Layered Na2Ti3O7/MgNaTi3O7/Mg0.5NaTi3O7 Nanoribbons as High-Performance Anode of Rechargeable Mg-Ion Batteries