High rate capability and long cycle stability of Cr₂O₃ anode with CNTs for lithium ion batteries

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• 作者：Syed Mustansar Abbas^a ; ^{qau_abbas@yahoo.com" class="auth_mail" title="E-mail the corresponding author} ; ^{abbas.aqu@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Nisar Ahmad^a ; ^{nisar_shawar@yahoo.com" class="auth_mail" title="E-mail the corresponding author} ; Ata-ur-Rehman^b ; Usman Ali Rana^c ; Salah Ud-Din Khan^c ; Shabbir Hussain^d ; ^e ; Kyung-Wan Nam^f
• 关键词：Carbon nanotubes ; Nanocomposites ; Porous materials ; Lithium ion battery ; Cr2O3
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：10 September 2016
• 年：2016
• 卷：212
• 期：Complete
• 页码：260-269
• 全文大小：2803 K

文摘

The present study describes the synthesis of nanocomposite materials based on chromium oxide (Cr₂O₃) nanoparticles and carbon nanotubes (CNTs) (Cr₂O₃–CNT_(x%)) by in-situ chemical co-precipitation method. The physical studies of these materials using a wide range of analytical techniques reveal high surface area and narrow pore size distribution of these nanocomposite materials, indicating homogenous dispersion of Cr₂O₃ nanoparticles (particle sizes ∼20-30 nm) on the surface of CNTs. The first cycle discharge capacity of 1120 mAhg-1${\text{mAhg}}^{\text{-1}}$ for electrodes fabricated from Cr₂O₃ alone, which is improved for Cr₂O₃–CNT_(0.08%) nanocomposite (1199 mAhg-1${\text{mAhg}}^{\text{-1}}$). This nanocomposite material achieved an overall reversible capacity of 995.3 mAhg-1${\text{mAhg}}^{\text{-1}}$ after 200 cycles, which can be attributed to the high surface area and the large mesoporous volume of Cr₂O₃ nanoparticles interconnected with highly conducting network of CNTs. At higher current densities, the Cr₂O₃–CNT_(x%) nanocomposite electrodes exhibited high lithium storage capacity compared to the electrode fabricated from Cr₂O₃ nanoparticles alone. Overall, the Cr₂O₃–CNT_(0.08%) nanocomposite electrode displayed high stability under varying current rates with overall high capacity retention and highest reversible capacity of 719 mAhg-1${\text{mAhg}}^{\text{-1}}$ at a current rate of 2000 mAhg-1${\text{mAhg}}^{\text{-1}}$. This highly enhanced rate capability and excellent cycling stability of Cr₂O₃–CNT_(0.08%) nanocomposite electrode can be ascribed to the synergistic effect of CNTs (anchored with the Cr₂O₃ nanoparticles). The outcome of this study offers a possibility of improving lithium ion storage of Cr₂O₃ nanoparticles by carefully controlling their size and shape along with the use of a suitable buffering matrix like CNTs.