scholarly journals Kinetic pathways of ionic transport in fast-charging lithium titanate

Science ◽  
2020 ◽  
Vol 367 (6481) ◽  
pp. 1030-1034 ◽  
Author(s):  
Wei Zhang ◽  
Dong-Hwa Seo ◽  
Tina Chen ◽  
Lijun Wu ◽  
Mehmet Topsakal ◽  
...  
Keyword(s):  
Ground State ◽  
Electrode Materials ◽  
Rate Capability ◽  
Lithium Titanate ◽  
High Rate ◽  
Phase Reaction ◽  
Two Phase ◽  
Fast Charging ◽  
Kinetic Mechanisms ◽  
Electron Energy Loss

Fast-charging batteries typically use electrodes capable of accommodating lithium continuously by means of solid-solution transformation because they have few kinetic barriers apart from ionic diffusion. One exception is lithium titanate (Li4Ti5O12), an anode exhibiting extraordinary rate capability apparently inconsistent with its two-phase reaction and slow Li diffusion in both phases. Through real-time tracking of Li+ migration using operando electron energy-loss spectroscopy, we reveal that facile transport in Li4+xTi5O12 is enabled by kinetic pathways comprising distorted Li polyhedra in metastable intermediates along two-phase boundaries. Our work demonstrates that high-rate capability may be enabled by accessing the energy landscape above the ground state, which may have fundamentally different kinetic mechanisms from the ground-state macroscopic phases. This insight should present new opportunities in searching for high-rate electrode materials.

Highly ordered nanoscale phosphomolybdate-grafted polyaniline/metal hybrid layered structures prepared via secondary sputtering phenomenon as high-performance pseudocapacitor electrodes

2021 ◽  
Author(s):  
Eun Seop Yoon ◽  
Bong Gill Choi ◽  
Hwan-Jin Jeon
Keyword(s):  
Electron Transfer ◽  
Aspect Ratio ◽  
Electrochemical Performance ◽  
High Aspect Ratio ◽  
High Performance ◽  
Electrode Materials ◽  
Rate Capability ◽  
High Specific Capacitance ◽  
High Rate ◽  
Large Area

Abstract The development of energy storage electrode materials is important for enhancing the electrochemical performance of supercapacitors. Despite extensive research on improving electrochemical performance with polymer-based materials, electrode materials with micro/nanostructures are needed for fast and efficient ion and electron transfer. In this work, highly ordered phosphomolybdate (PMoO)-grafted polyaniline (PMoO-PAI) deposited onto Au hole-cylinder nanopillar arrays is developed for high-performance pseudocapacitors. The three-dimensional nanostructured arrays are easily fabricated by secondary sputtering lithography, which has recently gained attention and features a high resolution of 10 nm, a high aspect ratio greater than 20, excellent uniformity/accuracy/precision, and compatibility with large area substrates. These 10nm scale Au nanostructures with a high aspect ratio of ~30 on Au substrates facilitate efficient ion and electron transfer. The resultant PMoO-PAI electrode exhibits outstanding electrochemical performance, including a high specific capacitance of 114 mF/cm2, a high-rate capability of 88%, and excellent long-term stability.

Hollow CoP spheres assembled by porous nanosheets as high-rate and ultra-stable electrode for advanced supercapacitors

2021 ◽  
Author(s):  
Li Sun ◽  
Zhenbin Xie ◽  
Aiping Wu ◽  
Chungui Tian ◽  
Dongxu Wang ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Rate Capability ◽  
High Rate ◽  
High Rate Capability ◽  
Porous Nanosheets

The electrode materials with a high rate capability and excellent recycled ability are vitally critical for building the supercapacitors, but it synthesis remains a challenge. Herein, we have constructed the...

Operando XRD study of LiMn1.5Ni0.5O4 high-voltage cathode under high-rate charge-discharge reaction

2019 ◽  
Vol 34 (S1) ◽  
pp. S8-S13
Author(s):  
T. Konya ◽  
Y. Shiramata ◽  
T. Nakamura
Keyword(s):  
Volume Change ◽  
Low Voltage ◽  
High Rate ◽  
Insertion Reaction ◽  
Phase Reaction ◽  
Two Phase ◽  
Voltage Range ◽  
Lattice Volume ◽  
Rate Determining Step ◽  
Spinel Cathode

Structural variation of LiMn1.5Ni0.5O4 spinel cathode during the Li+ extraction/insertion reaction was studied using operando X-ray diffraction. It was found that the reaction in the voltage range from 3.5 to 4.9 V consisted of two consecutive two-phase reactions, where three spinel phases of LiMn1.5Ni0.5O4, Li0.5Mn1.5Ni0.5O4 and Mn1.5Ni0.5O4 were identified and the lattice volume change in the whole reaction was evaluated as 6%. The reactions were symmetric and reversible under low-current conditions, but some asymmetries were detected during high current operation. Furthermore, a two-phase reaction between cubic and tetragonal phases was observed in the low-voltage reaction at 2.1–3.5 V, where the lattice volume change was approximately 4.9%. The rate-determining step was discussed based on these operando results.

A high rate capability and long lifespan symmetric sodium-ion battery system based on a bipolar material Na2LiV2(PO4)3/C

2018 ◽  
Vol 6 (21) ◽  
pp. 9962-9970 ◽  
Author(s):  
Meng Li ◽  
Zonglin Zuo ◽  
Jianqiu Deng ◽  
Qingrong Yao ◽  
Zhongmin Wang ◽  
...  
Keyword(s):  
Anode Material ◽  
Rate Capability ◽  
Sodium Ion ◽  
High Rate ◽  
Sodium Ion Battery ◽  
High Rate Capability ◽  
Two Phase ◽  
Battery System

A rhombohedral structured two-phase Na2LiV2(PO4)3/C nanocomposite was synthesized and employed as both cathode and anode material.

scholarly journals Synthesis of Hierarchical Graphene-MnO2 Nanowire Composites with Enhanced Specific Capacitance

2019 ◽  
Vol 31 (8) ◽  
pp. 1709-1718
Author(s):  
T. Veldevi ◽  
K. Thileep Kumar ◽  
R.A. Kalaivani ◽  
S. Raghu ◽  
A.M. Shanmugharaj
Keyword(s):  
Surface Area ◽  
Electrode Materials ◽  
High Surface ◽  
Specific Capacity ◽  
High Surface Area ◽  
Rate Capability ◽  
Sulfate Solution ◽  
High Rate ◽  
Chemical Compositions ◽  
Structure Morphology

Hierarchical nanostructured graphene–manganese dioxide nanowire (G-MnO2-NW) composites have been prepared by hydrothermal synthesis route using water/1-decanol as the medium. Synthesized materials were analyzed using various characterization tools to corroborate their chemical compositions, structure/morphology and surface area. Electrochemical measurements of the synthesized G-MnO2-NW electrode materials delivered the highest specific capacity (255 Fg-1), high rate capability and improved cycling stability at 0.5 Ag–1 in 1M sodium sulfate solution and this fact may be attributed to its high surface area and porosity. Moreover, synthesized G-MnO2-NW electrodes displayed better energy and power density, when compared to the MnO2-NW based electrodes.

scholarly journals Stable Copper Tin Sulfide Nanoflower Modified Carbon Quantum Dots for Improved Supercapacitors

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Zhen Bi ◽  
Lanyan Huang ◽  
Chaoqun Shang ◽  
Xin Wang ◽  
Guofu Zhou
Keyword(s):  
Quantum Dots ◽  
Volume Change ◽  
Electrode Materials ◽  
Rate Capability ◽  
Carbon Quantum Dots ◽  
High Rate ◽  
Electrochemical Performances ◽  
Tin Sulfide ◽  
Transmission Electron ◽  
Tin Sulfides

Copper tin sulfides (CTSs) have widely been investigated as electrode materials for supercapacitors owing to their high theoretical pseudocapacitances. However, the poor intrinsic conductivity and volume change during redox reactions hindered their electrochemical performances and broad applications. In this study, carbon quantum dots (CQDs) were employed to modify CTSs. The structures and morphologies of obtained materials were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD revealed CTSs were composed of Cu2SnS3 and Cu4SnS4, and TEM suggested the decoration of CQDs on the surface of CTSs. With the decoration of CQDs, CTSs@CQDs showed a remarkable specific capacitance of 856 F·g−1 at 2 mV·s−1 and a high rate capability of 474 F·g−1 at 50 mV·s−1, which were superior to those of CTSs (851 F·g−1 at 2 mV·s−1 and 192 F·g−1 at 50 mV·s−1, respectively). This was mainly ascribed to incorporation of carbon quantum dots, which improved the electrical conductivity and alleviated volume change of CTSs during charge/discharge processes.

A novel fabrication of nitrogen-containing carbon nanospheres with high rate capability as electrode materials for supercapacitors

RSC Advances ◽  
2015 ◽  
Vol 5 (16) ◽  
pp. 12034-12042 ◽  
Author(s):  
Hui Peng ◽  
Guofu Ma ◽  
Kanjun Sun ◽  
Jingjing Mu ◽  
Xiaozhong Zhou ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Rate Capability ◽  
High Rate ◽  
Carbon Nanospheres ◽  
High Rate Capability ◽  
Different Temperatures

Nitrogen-containing polyaniline-based carbon nanospheres (C-PANI) with diameters of about 200 nm are prepared through a direct carbonization method using polyaniline (PANI) nanospheres as carbon precursors at different temperatures.

Sign in / Sign up

Export Citation Format

Share Document