Size‐Tunable Olive‐Like Anatase TiO₂ Coated with Carbon as Superior Anode for Sodium‐Ion Batteries

Abstract

Olive-shaped anatase TiO with tunable sizes in nanoscale are designed employing polyvinyl alcohol (PVA) as structure directing agents to exert dramatic impacts on structure shaping and size manipulation. Notably, the introduced PVA simultaneously serves as carbon sources, bringing about a homogenous carbon layer with intimate coupling interfaces for boosted electronic conductivity. Constructed from tiny crystalline grains, the uniformly dispersed carbon-coated TiO nano-olives (TOC) possess subtle loose structure internally for prompt Na transportations. When utilized for sodium-ion storage, the size effects are increasingly significant at high charge-discharge rates, leading to the much superior rate performances of TOC with the smallest size. Bestowed by the improved Na adsorption and diffusion kinetics together with the promoted electron transfer, it delivers a high specific capacity of 267 mAh g at 0.1 C (33.6 mA g ) and sustains 110 mAh g at a rather high rate of 20 C. Even after cycled at 10 C over 1000 cycles, a considerable capacity of 125 mAh g with a retention of 94.6% is still obtained, highlighting its marvelous long-term cyclability and high-rate capabilities.

Advanced Phosphorus‐Based Materials for Lithium/Sodium‐Ion Batteries: Recent Developments and Future Perspectives

“…Besides, limited natural lithium source (0.065%, as shown in Figure 1a) with its uneven distribution (mainly in South America) in the Earth's crust, and the high costs of production are bound to exert a negative impact toward meeting large-scale energy storage requirements in our modern society. [15][16][17][18][19] In spite of many breakthroughs that have been achieved, the development of SIBs is relatively slow and immature in comparison to LIBs mainly because of the larger radius of Na + (1.09 Å vs 0.76 Å of Li + ). [14] In recent years, taking sodium's superiority in cost and abundance (2.75%, Figure 1a) into consideration, sodium-ion batteries (SIBs) have attracted increasing research interest all over the world and been regarded as one of the most promising and competitive ones to LIBs to some extent.…”

Bimetal-organic-framework derived CoTiO3 mesoporous micro-prisms anode for superior stable power sodium ion batteries

“…As present in Table 1, the asprepared pure CoTiO 3 micro-prisms also deliver significantly higher capacity and better rate capability than typical carbon materials [9][10][11], and pure TiO 2 anode materials, meanwhile, show similar or even better electrochemical performance with N, Mo, Sn doped TiO 2 and ultra-small sized TiO 2 [13][14][15][16][17][18][19][20][21][22][23][24]. The better electrical conductivity of CoTiO 3 than NiTiO 3 , TiO 2 , because of the narrower band gap of CoTiO 3 (2.34 eV) than NiTiO 3 (3.02 eV) and TiO 2 (3.3 eV), should be one of the reason responsible for the much enhanced sodium ion storage performance [31,32].…”

“…However, the poor cyclic stability due to the larger volume change is the intrinsic drawbacks as anode materials for SIBs. Lately, titanium oxides based nanostructured materials [13][14][15][16][17][18][19][20][21][22][23][24][25], have been extensively studied as promising candidate anode materials due to their relatively smaller volume change than other transition metal compounds and better cyclic stability. However, their capacities and rate capability are similar or even lower than carbon anodes, which are the main challenge for their application in both high energy and high power density type batteries.…”

“…However, their capacities and rate capability are similar or even lower than carbon anodes, which are the main challenge for their application in both high energy and high power density type batteries. Hereby, great ef-forts have been made to further enhance the power and cyclic stability of titanium-based compounds by the following methods, including minimizing the particle size to increase the electrochemical reactivity of TiO 2 [13], introducing conductive carbon coating/hybrid to improve the poor electric conductivity of TiO 2 [13][14][15][16], constructing porous and hierarchical nanostructure to increase the interaction surface area between active TiO 2 and electrolyte for further enhance the rate capability of TiO 2 [17][18][19][20][21][22][23][24][25].…”

In-situ phase transition to form porous h-MoO3@C nanofibers with high stability for Li+/Na+ storage

“…On the other hand, sodium ion batteries (SIBs) have recently received wide publicity as an energy storage system due to more natural abundance of Na reserves [10,11]. The theoretical capacity of the traditional commercial graphite anode is only 372 mA h g −1 for LIBs [12,13], even lower for SIBs [14,15], limiting the application of high efficiency energy demand with high stability both for LIBs and SIBs. Thus, it has been drawing wide attention to develop new anode materials, which not only have relatively high capacity but also maintain good cycling stability.…”