Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
Chem Asian J. 2010 Apr 1;5(4):792-8. doi: 10.1002/asia.200900494.
We have synthesized spinel type cobalt-doped LiMn(2)O(4) (LiMn(2-y)Co(y)O(4), 0</=y</=0.367), a cathode material for a lithium-ion battery, with hierarchical sponge structures via the cobalt-doped MnCO(3) (Mn(1-x)Co(x)CO(3), 0</=x</=0.204) formed in an agar gel matrix. Biomimetic crystal growth in the gel matrix facilitates the generation of both an homogeneous solid solution and the hierarchical structures under ambient condition. The controlled composition and the hierarchical structure of the cobalt-doped MnCO(3) precursor played an important role in the formation of the cobalt-doped LiMn(2)O(4). The charge-discharge reversible stability of the resultant LiMn(1.947)Co(0.053)O(4) was improved to ca. 12 % loss of the discharge capacity after 100 cycles, while pure LiMn(2)O(4) showed 24 % loss of the discharge capacity after 100 cycles. The parallel control of the hierarchical structure and the composition in the precursor material through a biomimetic approach, promises the development of functional materials under mild conditions.
我们通过在琼脂凝胶基质中形成的钴掺杂 MnCO3（Mn1-xCoxCO3，0≤x≤0.204），合成了具有分级海绵结构的尖晶石型钴掺杂 LiMn（2）O4（LiMn（2-y）CoyO4，0≤y≤0.367），这是一种锂离子电池的正极材料。凝胶基质中的仿生晶体生长有利于在环境条件下生成均匀的固溶体和分级结构。钴掺杂 MnCO3 前体的受控组成和分级结构对钴掺杂 LiMn（2）O4 的形成起着重要作用。所得 LiMn（1.947）Co（0.053）O4 的充放电可逆稳定性提高到约 100 次循环后放电容量损失约 12%，而纯 LiMn（2）O4 在 100 次循环后放电容量损失约 24%。通过仿生方法对前体材料的分级结构和组成进行平行控制，有望在温和条件下开发功能材料。
