Amorphous monodispersed hard carbon micro-spherules derived from biomass as a high performance negative electrode material for sodium-ion batteries

2015 ◽  
Vol 3 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Yunming Li ◽  
Shuyin Xu ◽  
Xiaoyan Wu ◽  
Juezhi Yu ◽  
Yuesheng Wang ◽  
...  

This paper reports monodispersed hard carbon micro-spherules with a high energy density, high initial coulombic efficiency and excellent cycle performance.

2016 ◽  
Vol 4 (34) ◽  
pp. 13046-13052 ◽  
Author(s):  
Pin Liu ◽  
Yunming Li ◽  
Yong-Sheng Hu ◽  
Hong Li ◽  
Liquan Chen ◽  
...  

This study reports a hard carbon material derived from a waste biomass of corn cob and the influence of carbonized temperature on electrochemical performance. This study provides a promising anode material with low cost, high initial coulombic efficiency and excellent cycle performance, making sodium-ion batteries closer to practical applications.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Qiulong Wei ◽  
Qidong Li ◽  
Yalong Jiang ◽  
Yunlong Zhao ◽  
Shuangshuang Tan ◽  
...  

AbstractHigh-performance and low-cost sodium-ion capacitors (SICs) show tremendous potential applications in public transport and grid energy storage. However, conventional SICs are limited by the low specific capacity, poor rate capability, and low initial coulombic efficiency (ICE) of anode materials. Herein, we report layered iron vanadate (Fe5V15O39 (OH)9·9H2O) ultrathin nanosheets with a thickness of ~ 2.2 nm (FeVO UNSs) as a novel anode for rapid and reversible sodium-ion storage. According to in situ synchrotron X-ray diffractions and electrochemical analysis, the storage mechanism of FeVO UNSs anode is Na+ intercalation pseudocapacitance under a safe potential window. The FeVO UNSs anode delivers high ICE (93.86%), high reversible capacity (292 mAh g−1), excellent cycling stability, and remarkable rate capability. Furthermore, a pseudocapacitor–battery hybrid SIC (PBH-SIC) consisting of pseudocapacitor-type FeVO UNSs anode and battery-type Na3(VO)2(PO4)2F cathode is assembled with the elimination of presodiation treatments. The PBH-SIC involves faradaic reaction on both cathode and anode materials, delivering a high energy density of 126 Wh kg−1 at 91 W kg−1, a high power density of 7.6 kW kg−1 with an energy density of 43 Wh kg−1, and 9000 stable cycles. The tunable vanadate materials with high-performance Na+ intercalation pseudocapacitance provide a direction for developing next-generation high-energy capacitors.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Lei Zheng ◽  
Feng Guo ◽  
Tuo Kang ◽  
Yingzhu Fan ◽  
Wei Gu ◽  
...  

AbstractLithium metal is regarded as the ultimate negative electrode material for secondary batteries due to its high energy density. However, it suffers from poor cycling stability because of its high reactivity with liquid electrolytes. Therefore, continuous efforts have been put into improving the cycling Coulombic efficiency (CE) to extend the lifespan of the lithium metal negative electrode. Herein, we report that using dual-salt additives of LiPF6 and LiNO3 in an ether solvent-based electrolyte can significantly improve the cycling stability and rate capability of a Li-carbon (Li-CNT) composite. As a result, an average cycling CE as high as 99.30% was obtained for the Li-CNT at a current density of 2.5 mA cm–2 and an negative electrode to positive electrode capacity (N/P) ratio of 2. The cycling stability and rate capability enhancement of the Li-CNT negative electrode could be attributed to the formation of a better solid electrolyte interphase layer that contains both inorganic components and organic polyether. The former component mainly originates from the decomposition of the LiNO3 additive, while the latter comes from the LiPF6-induced ring-opening polymerization of the ether solvent. This novel surface chemistry significantly improves the CE of Li negative electrode, revealing its importance for the practical application of lithium metal batteries.


2021 ◽  
Author(s):  
yajun JI ◽  
Fei Chen ◽  
Shufen Tan ◽  
Fuyong Ren

Abstract Transition metal oxides are generally designed as hybrid nanostructures with high performance for supercapacitors by enjoying the advantages of various electroactive materials. In this paper, a convenient and efficient route had been proposed to prepare hierarchical coral-like MnCo2O4.5@Co-Ni LDH composites on Ni foam, in which MnCo2O4.5 nanowires were enlaced with ultrathin Co-Ni layered double hydroxides nanosheets to achieve high capacity electrodes for supercapacitors. Due to the synergistic effect of shell Co-Ni LDH and core MnCo2O4.5, the outstanding electrochemical performance in three-electrode configuration was triggered (high area capacitance of 5.08 F/cm2 at 3 mA/cm2 and excellent rate capability of maintaining 61.69 % at 20 mA/cm2), which is superior to those of MnCo2O4.5, Co-Ni LDH and other metal oxides based composites reported. Meanwhile, the as-prepared hierarchical MnCo2O4.5@Co-Ni LDH electrode delivered improved electrical conductivity than that of pristine MnCo2O4.5. Furthermore, the as-constructed asymmetric supercapacitor using MnCo2O4.5@Co-Ni LDH as positive and activated carbon as negative electrode presented a rather high energy density of 220 μWh/cm2 at 2400 μW/cm2 and extraordinary cycling durability with the 100.0 % capacitance retention over 8000 cycles at 20 mA/cm2, demonstrating the best electrochemical performance compared to other asymmetric supercapacitors using metal oxides based composites as positive electrode material. It can be expected that the obtained MnCo2O4.5@Co-Ni LDH could be used as the high performance and cost-effective electrode in supercapacitors.


2018 ◽  
Vol 6 (45) ◽  
pp. 22840-22850 ◽  
Author(s):  
Meiling Kang ◽  
Yingying Wu ◽  
Xin Huang ◽  
Kaiqiang Zhou ◽  
Zhigao Huang ◽  
...  

A high-performance hybrid sodium-ion capacitor was developed through the engineering of a TiO2 anode to achieve record high initial coulombic efficiency.


2020 ◽  
Vol 8 (45) ◽  
pp. 24040-24052
Author(s):  
Bobby Singh Soram ◽  
Jiu Yi Dai ◽  
Ibomcha Singh Thangjam ◽  
Nam Hoon Kim ◽  
Joong Hee Lee

One-step electrodeposited MoS2@Ni-mesh as a high-performance negative electrode; a high energy density flexible and transparent asymmetric solid-state supercapacitor is fabricated.


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