Optimization of nonatitanate electrodes for sodium-ion batteries

Abstract

NaTi3O6(OH)·2H2O, also known as “sodium nonatitanate” (NNT) can undergo reversible sodium (de)insertion at low potentials centered around 0.3 V.

Sodium diffusion and dynamics in Na2Ti3O7: neutron scattering and ab initio simulations

“…However, they can be used for applications where energy density requirements are not as stringent, 7 and may be commercially viable. 8–12 The first sodium–sulfur battery was developed after the discovery of the high-temperature ionic conductor β-alumina, NaAl 11 O 17 . 13 Since then, many Na-ion conductors have been discovered, 14–17 including the sulfide compounds 18–20 that exhibit very high ionic conductivity suitable for application in batteries.…”

“…The energy density of sodium-ion batteries is some 30 % lower 6 than that of lithium-ion batteries. However, they can be used for applications where energy density requirements are not as stringent 7 , and may be commercially viable [8][9][10][11][12] . The first sodiumsulfur battery was developed after the discovery of the high-temperature ionic conductor β-alumina,…”

A layered nonstoichiometric lepidocrocite-type sodium titanate anode material for sodium-ion batteries

“…Sodium titanates are another promising family of anode materials. 8 Depending on structure (layered or tunnel), a considerable amount of Na + can be reversibly stored (e.g., 200 mAh g -1 for sodium nonatitanate) 9 at low potentials (in the range of 0.3 ~ 0.6 V vs. Na + /Na). 5,10,11 We recently reported on several candidate sodium titanate anodes 5,9,11,12 with lepidocrocite-type structures.…”

“…8 Depending on structure (layered or tunnel), a considerable amount of Na + can be reversibly stored (e.g., 200 mAh g -1 for sodium nonatitanate) 9 at low potentials (in the range of 0.3 ~ 0.6 V vs. Na + /Na). 5,10,11 We recently reported on several candidate sodium titanate anodes 5,9,11,12 with lepidocrocite-type structures. These materials have the general formula Na x Ti 2-y M y O 4 (where M represents a variety of substituents such as Li + or Mg 2+ ).…”

Heterostructured Lepidocrocite Titanate-Carbon Nanosheets for Electrochemical Applications

“…Previously, our group reported on several Na + insertion anodes based on layered titanates showing high capacities (200 mAh g -1 ) and low sodium intercalation potentials (~0.3 -0.6 V vs. Na + /Na). [10][11][12][13] Some of them are isostructural to the lepidocrocite mineral γ-FeOOH, which has a corrugated layered structure. Lepidocrocite-type titanates have the general formula of AxTi2−y MyO4, where A = K, Rb, or Cs, and M represents Li, Mg, Mn, Fe, Co, Ni, Cu, Zn or a vacancy.…”