Nanostructured Ti-based anode materials for Na-ion batteries

Abstract

With the shortage of fossil energy and global climate change, renewable energy sources offer the most promise to these challenges. However, the intermittence of energy sources such as solar and wind requires sustainable energy-storage technologies. Nowadays, electrochemical energy-storage technologies and applications have attracted much attention, including portable electric devices, electric vehicles and smart power grids.Lithium-ion batteries (LIBs) have been widely applied in these areas because of their safety, portability and high energy density. Nevertheless, the resources of lithium are limited and the vast consumption of lithium has pushed up the price of lithium compounds, urging people to search for resourceful materials. Sodium can be a promising alternative for its high abundance and low cost. Furthermore, titanium-based materials have become a hotspot of anode materials in sodium-ion batteries (SIBs), taking advantages of their high 2 safety and structural stability. In this review, we summarize the recent advances on Tibased anode materials for SIB applications. We highlight the design and engineering of the Ti-based nanoarchitectures, especially emphasize on the effective enhancement in performance and the related sodium-storage mechanism. 3 elements on earth. Sodium becomes a suitable candidate due to the high abundance and low cost as well as the similar redox potential to lithium (ENa+/Na = -2.7 V versus standard hydrogen electrode, only 0.3 V above that of lithium). In fact, the research on sodium-ion batteries (SIBs) is not newly developed. The discovery of high-temperature solid-state sodium conductors shed light on sodium electrochemistry. 3 After that, sodium batteries operating at high temperature attracted much attention with the discovery of NASICON. 4 Several decades later, along with the investigation of LIBs in the 1980s, the concept of SIBs was put forward. 5 Whereas LIBs received rapid progress and advanced technology, SIBs faded out researchers' sight gradually.In the past few years, ambient-temperature SIBs with intercalation materials have gone through a revitalization due to the sustainable advantages and large-scale applications.Plenty of cathodes for SIBs have been studied while suitable anode materials are quite limited. 6, 7 Although graphite is widely used as the anode in commercialized LIBs, it shows poor capacity performance in SIBs. Attempts have been made to modify graphite, but there are still some problems demanding solutions. 8 Ti-based materials, including titanium dioxide and a series of Ti-containing compounds, have been widely investigated in photocatalysis, solar cells, and water splitting. In particular, owing to the exceptional chemical durability and crystalline structural diversity, Ti-based materials such as TiO2 [9][10][11][12][13][14][15][16] and Li4Ti5O12 17-20 have now been recently explored in energy-storage areas. In this review, we focus on the recent progress on nanostructured Ti-based anode materials for SIBs. The enhanced performances through ...

Surface‐Engineered Black Niobium Oxide@Graphene Nanosheets for High‐Performance Sodium‐/Potassium‐Ion Full Batteries

“…However, concerns such as limited lithium sources and safety issues have greatly hampered the further LIB applications . To address this issue, sodium‐ion battery (SIB) and potassium‐ion battery (PIB) technologies become potential alternatives because of their rich abundance and high theoretical capacities . However, the much larger ion sizes of sodium and potassium have led to increased volume changes and sluggish redox kinetics during charging/discharging cycles .…”

Phosphorus‐Doping‐Induced Surface Vacancies of 3D Na2Ti3O7 Nanowire Arrays Enabling High‐Rate and Long‐Life Sodium Storage

“…Recently, Ti‐based materials have attracted much attention because of their environmental benignity, abundant resources, and low cost . Na 2 Ti 3 O 7 is a promising anode material for SIBs due to its open layered framework, which is capable of exhibiting high specific capacity and high ionic conductivity . However, the low electrical conductivity of Na 2 Ti 3 O 7 leads to fast capacity fading and poor cycling stability .…”

“…[21,22] Na 2 Ti 3 O 7 is ap romising anode material for SIBs due to its open layered framework, which is capable of exhibiting high specificc apacity and high ionic conductivity. [22] However, the low electrical conductivity of Na 2 Ti 3 O 7 leads to fast capacity fading and poor cyclings tability. [23,24] Turning the surfacee lectron configuration of metal oxides by creating vacancies in the crystal lattice is ah ighly effective strategy to improve the electrical conductivity and sodiums torage performance.…”

Flexible Na batteries

“…Natural wood fibers and oxidized wood fibers have been successfully used to fabricate paper-like anodes used in NIBs, as shown in Figure 3A, where wood fibers were oxidized by using 2,2,6,6-tetramethylpiperidine-1-oxyl-mediated. 57,58 However, almost all of these compounds suffer from poor electrical conductivity and ionic conductivity. The oxidized carbon paper delivered a reversible capacity of~260 mAh g −1 with an initial coulombic efficiency of~72%.…”

“…34,[54][55][56] Due to the low redox potential of the Ti 4+/3+ couple of 0.4-1.0 V, Ti-based oxides have been widely used as Na battery anodes on the basis of an intercalation-type mechanism. 57,58 However, almost all of these compounds suffer from poor electrical conductivity and ionic conductivity. Nanocrystallization treatments and conductive material coatings have been found to improve their electrochemical performance.…”