Superior Stable Self‐Healing SnP 3 Anode for Sodium‐Ion Batteries

Phosphorus and tin phosphide based materials that are extensively researched as the anode for Na‐ion batteries mostly involve complexly synthesized and sophisticated nanocomposites limiting their commercial viability. This work reports a Sn4P3‐P (Sn:P = 1:3) @graphene nanocomposite synthesized with a novel and facile mechanochemical method, which exhibits unrivalled high‐rate capacity retentions of >550 and 371 mA h g−1 at 1 and 2 A g−1, respectively, over 1000 cycles and achieves excellent rate capability (>815, ≈585 and ≈315 mA h g−1 at 0.1, 2, and 10 A g−1, respectively).

Section: A High-rate and Ultrastable Sodium Ion Anode Based On A Novementioning

confidence: 99%

Section: A High-rate and Ultrastable Sodium Ion Anode Based On A Novementioning

confidence: 99%

A High‐Rate and Ultrastable Sodium Ion Anode Based on a Novel Sn₄P₃‐P@Graphene Nanocomposite

Peng

Mulder

2017

“…Na ion batteries attract signifi cant research interest since they provide potentially high energy density while using low cost and abundant sodium as the active ion. [1][2][3][4][5] Due to the analogy between Li and Na ions, different types of materials that have been applied in Li-ion batteries are also studied for application in Na ion batteries and vice versa. [6][7][8][9] Si has been extensively investigated since it has high theoretical lithiation capacity up to Li 4.4 Si.…”

mentioning

confidence: 99%

Reversible Na‐Ion Uptake in Si Nanoparticles

Swaans²,

Basak

et al. 2015

111

103

appear to be nicely spherical, whereas the surface layer has been oxidized. A native oxidation layer grows on the surface of individual Si nanoparticles when they are exposed to traces of air after synthesis. The presence of such limited pacifying oxide layer appeared of advantage for the further processing in air. The average thickness of the oxidation layer is around 1.2 nm, and it is amorphous when observed by X-ray diffraction (XRD) (Figure 1 c), i.e., only peaks corresponding to crystalline Si are visible. For a particle with a size of 20 nm Si in diameter and 1.2 nm outer layer of SiO 2 , the volume percentage of SiO 2 is 28.8%. Raman spectra (Figure 1 d) on the sample report that both crystalline and amorphous Si exist and the amount of amorphous Si is signifi cant (c-Si:a-Si = 0.39:0.61; quantitative analysis in the Supporting Information). To determine the amount of oxygen in the sample, thermogravimetric analysis (TGA) is carried out by heating the Si NP sample under a mixture of O 2 /Ar gas and fully oxidizing Si into SiO 2 . The result indicates that the amount of Si accounts for 69.0 wt% of the sample ( Figure S2, Supporting Information), i.e., Si:SiO 2 = 0.83:0.17 in mole. Meanwhile, the volume fraction from the estimated mass ratio above is 28.2% and is in good quantitative agreement with the one estimated from TEM.Galvanostatic tests on the Si NP electrode are performed using different dis-/charge currents between applied potentials of 0.01 and 2.8 V. In this paper, all specifi c currents applied are calculated with respect to the mass of Si. De-/sodiation capacities of Si stated in this paper are the capacities after subtracting the capacity of the super P carbon black ( Figure S3, Supporting Information), and excluding inactive SiO x inside the sample.Figure 2 a demonstrates an initial sodiation capacity of 1027 mAh g −1 for Si at 20 mA g −1 , which is higher than the theoretical capacity (954 mAh g −1 for NaSi). A large part of this initial capacity is attributed to the irreversible formation of a solid electrolyte interface (SEI) layer on the surface of Si in combination with some decomposition of electrolyte, and possibly also the irreversible formation of sodium silicate from reaction with SiO 2 . The subsequent Na ion extraction process achieves a capacity up to 270 mAh g −1 , indicating that a signifi cant Na fraction is stored reversibly, next to the large irreversible part. For the subsequent few cycles the sodiation capacity decreases from above 410 mAh g −1 to around 300 mAh g −1 but the desodiation capacity is relatively stable around 260 mAh g −1 . The Coulombic effi ciency grows gradually to >90%, after which the de-/sodiation capacity becomes relatively stable. After 100 cycles the reversible capacity retention reaches 248 mAh g −1 , which is 92% of the fi rst desodiation capacity; and the Coulombic efficiency declines slowly to 87% in this cycle test. Additionally, Figure 1 e shows that after charge/discharge for 100 cycles Si particles in this electrode got fractured into small g...

“…[64][65][66][67][68][69][70][71][72][73] By mimicking some natural features, e.g., self-healing ability of skin, self-rechargeable capability, some advanced energy-storage devices with similar features have been obtained. [74][75][76][77][78][79][80] In this review, we mainly focus on the typical progress in this emerging field of nature-inspired design and fabrication of energy-storage related materials and devices. Firstly, natureinspired exploration, preparation and modification of active materials are introduced.…”

Section: Introductionmentioning

confidence: 99%

Nature‐Inspired Electrochemical Energy‐Storage Materials and Devices

Wang

Yang

Guo

2016

152

Nature-inspired strategies have been proposed recently as novel and effective routines to address these challenges.(1) Specifically, the limited availability of mineral resources could hardly satisfy the booming requirement and subsequent production quantity of energystorage devices for long time, and will necessarily lead to their increasing price. [15,16] Moreover, the non-biodegradability of current energy-storage devices after their service lifetime will bring about tremendous electronic garbage. Thus, renewable, cheap and environment-friendly energy-storage related materials are greatly desired to substitute current components. [12,[17][18][19][20][21][22][23][24][25][26] In nature, its energy conversion and storage systems have been evolved for billions of years, and spawned highly efficient and well suited cellular respiration machineries in living organisms for external energy assimilation, metabolism and distribution. [27] In recent years, inspirations have been taken from nature to fabricate biomolecule-based electrode materials from renewable biomass. [28][29][30][31][32] For example, inspired by the electron shuttles functioning in extracellular electron transfer via reversible redox-cycling, man-made electrode materials with similar active functional groups have been explored. [33,34] In our newly reported work, supercapacitor employing redoxactive biomolecule as the faradic-type active material could even obtain a higher energy density than those of previous transition-metal-based supercapacitors. [35] (2) Another issue encountered by current energy-storage system arises from the laborious preparation processes of their energy-storage materials which usually adopt extreme conditions. In biological systems, assembly of complicated micro-organelles are precisely controlled with the aid of biotemplates. By mimicking the bio-assembly processes or utilizing appropriate biotemplates, facile preparation of energy-storage materials in mild conditions has been achieved. [36][37][38][39][40][41][42][43][44] (3) In rechargeable batteries and supercapacitors, the architecture of active materials always determines their cycle life and rate performance. [45][46][47][48] While the abundant examples of natural structures with known stableness, geometry configuration, surface wettability and mechanical property provide clues for rational design of nanostructured active materials with desired performance. [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63] (4) What's more, nature-inspired routines are also useful for rational design of ideal binders Currently, tremendous efforts are being devoted to develop high-performance electrochemical energy-storage materials and devices. Conventional electrochemical energy-storage systems are confronted with great challenges to achieve high energy density, long cycle-life, excellent biocompatibility and environmental friendliness. The biological energy metabolism and storage systems have appealing merits of high efficiency, sophisticated regulation, clean and renewabil...