Structural developments of artificial graphite scraps in further graphitization and its relationships with discharge capacity

2012 ◽  
Vol 75 ◽  
pp. 311-315 ◽  
Author(s):  
Chang-ling Fan ◽  
Huan He ◽  
Ke-he Zhang ◽  
Shao-chang Han
2011 ◽  
Vol 80-81 ◽  
pp. 332-336 ◽  
Author(s):  
Yan Xia ◽  
Mei Huang ◽  
Jun Ming Guo ◽  
Ying Jie Zhang

Effect of nitric acid and the burning time on the liquid combustion synthesis of spinel LiMn2O4 has been studied, using lithium nitrite and Manganese acetate as raw a material. The results show that the main phases are all LiMn2O4, which can be obtained at 400-600 oC. Before modified, the impurity is Mn3O4 or Mn2O3. After modified, the impurity is only Mn3O4. The aggregation obviously reduced after adding nitric acid, it is indicated that the crystalline increased. With the increasing temperatures, the modified particle size was increased and the aggregation reduced. The initial discharge capacity and cycle stability improved at some extent too. Its first discharge capacity was 104.6, 112.8 and 117.7mAh/g synthesized at 400, 500, 600 oC, respectively, and the 30th capacity retention rate were 84.89%, 80.67% and 73.24%.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 122
Author(s):  
Renwei Lu ◽  
Xiaolong Ren ◽  
Chong Wang ◽  
Changzhen Zhan ◽  
Ding Nan ◽  
...  

Lithium-ion hybrid capacitors (LICs) are regarded as one of the most promising next generation energy storage devices. Commercial activated carbon materials with low cost and excellent cycling stability are widely used as cathode materials for LICs, however, their low energy density remains a significant challenge for the practical applications of LICs. Herein, Na0.76V6O15 nanobelts (NaVO) were prepared and combined with commercial activated carbon YP50D to form hybrid cathode materials. Credit to the synergism of its capacitive effect and diffusion-controlled faradaic effect, NaVO/C hybrid cathode displays both superior cyclability and enhanced capacity. LICs were assembled with the as-prepared NaVO/C hybrid cathode and artificial graphite anode which was pre-lithiated. Furthermore, 10-NaVO/C//AG LIC delivers a high energy density of 118.9 Wh kg−1 at a power density of 220.6 W kg−1 and retains 43.7 Wh kg−1 even at a high power density of 21,793.0 W kg−1. The LIC can also maintain long-term cycling stability with capacitance retention of approximately 70% after 5000 cycles at 1 A g−1. Accordingly, hybrid cathodes composed of commercial activated carbon and a small amount of high energy battery-type materials are expected to be a candidate for low-cost advanced LICs with both high energy density and power density.


2017 ◽  
Vol 19 (26) ◽  
pp. 17270-17277 ◽  
Author(s):  
Yubin Niu ◽  
Maowen Xu ◽  
Chunlong Dai ◽  
Bolei Shen ◽  
Chang Ming Li

Na6.24Fe4.88(P2O7)4 is one of the intensively investigated polyanionic compounds and has shown high rate discharge capacity, but its relatively low electronic conductivity hampers the high performance of the batteries.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 319
Author(s):  
Ji-Hye Koo ◽  
Seung-Min Paek

Germanium/germanium oxide nanoparticles with theoretically high discharge capacities of 1624 and 2152 mAh/g have attracted significant research interest for their potential application as anode materials in Li-ion batteries. However, these materials exhibit poor long-term performance due to the large volume change of 370% during charge/discharge cycles. In the present study, to overcome this shortcoming, a Ge/GeO2/graphene composite material was synthesized. Ge/GeO2 nanoparticles were trapped between matrices of graphene nanosheets to offset the volume expansion effect. Transmission electron microscopy images revealed that the Ge/GeO2 nanoparticles were distributed on the graphene nanosheets. Discharge/charge experiments were performed to evaluate the Li storage properties of the samples. The discharge capacity of the bare Ge/GeO2 nanoparticles in the first discharge cycle was considerably large; however, the value decreased rapidly with successive cycles. Conversely, the present Ge/GeO2/graphene composite exhibited superior cycling stability.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1946 ◽  
Author(s):  
Hae-Jun Kwon ◽  
Sang-Wook Woo ◽  
Yong-Ju Lee ◽  
Je-Young Kim ◽  
Sung-Man Lee

The electrochemical performance of modified natural graphite (MNG) and artificial graphite (AG) was investigated as a function of electrode density ranging from 1.55 to 1.7 g∙cm−3. The best performance was obtained at 1.55 g∙cm−3 and 1.60 g∙cm−3 for the AG and MNG electrodes, respectively. Both AG, at a density of 1.55 g∙cm−3, and MNG, at a density of 1.60 g∙cm−3, showed quite similar performance with regard to cycling stability and coulombic efficiency during cycling at 30 and 45 °C, while the MNG electrodes at a density of 1.60 g∙cm−3 and 1.7 g∙cm−3 showed better rate performance than the AG electrodes at a density of 1.55 g∙cm−3. The superior rate capability of MNG electrodes can be explained by the following effects: first, their spherical morphology and higher electrode density led to enhanced electrical conductivity. Second, for the MNG sample, favorable electrode tortuosity was retained and thus Li+ transport in the electrode pore was not significantly affected, even at high electrode densities of 1.60 g∙cm−3 and 1.7 g∙cm−3. MNG electrodes also exhibited a similar electrochemical swelling behavior to the AG electrodes.


2021 ◽  
Author(s):  
Jinkwang Hwang ◽  
Rika Hagiwara ◽  
Hiroshi Shinokubo ◽  
Ji-Young Shin

Dual-ion sodium-organic secondary batteries were provided with antiaromatic porphyrinoid, NiNc as an active electrode material, which implemented inherent charge-discharge behaviors with high discharge capacity, high stability, high Coulombic efficiency with...


Energy ◽  
2015 ◽  
Vol 86 ◽  
pp. 638-648 ◽  
Author(s):  
Junfu Li ◽  
Lixin Wang ◽  
Chao Lyu ◽  
Liqiang Zhang ◽  
Han Wang

2018 ◽  
Vol 47 (35) ◽  
pp. 12337-12344 ◽  
Author(s):  
Xia Wu ◽  
Shi-Xi Zhao ◽  
Lü-Qiang Yu ◽  
Jin-Lin Yang ◽  
Ce-Wen Nan

Sulfur has been successfully employed into Li2MnSiO4 and results in a high initial discharge capacity and excellent cycling stability.


Sign in / Sign up

Export Citation Format

Share Document