Preparation of β-MnO2 nanocrystal/acetylene black composites for lithium batteries

被引:60
作者
Tang, WP
Yang, XJ
Liu, ZH
Ooi, K
机构
[1] Res Inst Solvothermal Technol, Takamatsu, Kagawa 7610301, Japan
[2] Natl Inst Adv Ind Sci & Technol, Marine Resources & Environm Res Inst, Takamatsu, Kagawa 7610395, Japan
关键词
D O I
10.1039/b306780g
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Composites consisting of beta-MnO2 nanocrystals and acetylene black were synthesized by thermal decomposition of Mn(NO3)(2) with acetylene black. The effects of heating temperature and specific surface area (S-BET) of the starting acetylene black on the formation and properties of the composite were investigated. The decomposition of Mn(NO3) 2 mixed with acetylene black progressed at a lower temperature than that of Mn(NO3) 2 alone. The formation and the size of beta-MnO2 nanocrystals depended strongly on the heating temperature (T) and S-BET of the starting acetylene black. The beta-MnO2/acetylene black composite could be produced for acetylene black of S-BET = 60 m(2) g(-1) at 160degreesC less than or equal to T less than or equal to 320degreesC and S-BET = 133 m(2) g(-1) at 160degreesC less than or equal to T less than or equal to 300degreesC. However, the composite could not be obtained for acetylene black with larger specific surface area (S-BET = 300 m(2) g(-1)). The size of beta-MnO2 nanocrystals decreases and their dispersion in the composites increases with an increase in the S-BET or the heating temperature. The lithium insertion behavior and voltage feature in the first discharge process depend strongly on the size of the beta-MnO2 nanocrystals as well as their dispersion. The electrochemical lithium insertion progressed topotactically for well-dispersed beta-MnO2 nanocrystals, retaining the framework of their rutile structure to permit a large amount of lithium insertion (Li/Mn = 1.15 in the solid). The charge/discharge curves showed a flat voltage plateau around 2.8 V and a stable cycling feature up to the 20th cycle. It is likely that the easy lattice expansion of beta-MnO2 nanocrystals along the a crystal axis plays an important role in the topotactic lithium insertion/extraction reactions.
引用
收藏
页码:2989 / 2995
页数:7
相关论文
共 14 条
  • [11] SYNTHESIS AND CHARACTERIZATION OF GAMMA-MNO2 FROM LIMN2O4
    THACKERAY, MM
    DEKOCK, A
    DEPICCIOTTO, LA
    PISTOIA, G
    [J]. JOURNAL OF POWER SOURCES, 1989, 26 (3-4) : 355 - 363
  • [12] TODOROKITES - A NEW FAMILY OF NATURALLY-OCCURRING MANGANESE OXIDES
    TURNER, S
    BUSECK, PR
    [J]. SCIENCE, 1981, 212 (4498) : 1024 - 1027
  • [13] SYNTHESIS AND STRUCTURAL ASPECTS OF LIMN2O4+/-DELTA AS A CATHODE FOR RECHARGEABLE LITHIUM BATTERIES
    YAMADA, A
    MIURA, K
    HINOKUMA, K
    TANAKA, M
    [J]. JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1995, 142 (07) : 2149 - 2156
  • [14] INSERTION OF LITHIUM INTO THE MANGANESE DIOXIDES - PYROLUSITE AND RAMSDELLITE
    ZACHAUCHRISTIANSEN, B
    WEST, K
    JACOBSEN, T
    SKAARUP, S
    [J]. SOLID STATE IONICS, 1994, 70 (pt 1) : 401 - 406