High-performance LiMnPO4/C nanoplates synthesized by negative pressure immersion and a solid state reaction using nanoporous Mn2O3 precursors
High-performance LiMnPO4/C nanoplates synthesized by negative pressure immersion and a solid state reaction using nanoporous Mn2O3 precursors
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DOI：
10.1039/c5ta02431e
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发表时间：
2015-07
影响因子：
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通讯作者：
Jugong Zheng;Cancan Qin;Tongfu Wu;Xie Shuangfei;Liang Ni;Peng Muyang;Tang Yuefeng;Yan-feng Chen
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文献类型：
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作者：
Jugong Zheng;Cancan Qin;Tongfu Wu;Xie Shuangfei;Liang Ni;Peng Muyang;Tang Yuefeng;Yan-feng Chen
由于LiMnPO 4的电化学动力学性能较差，制备高性能LiMnPO 4仍然是一个很大的障碍。为了克服这个问题，开发了一种由纳米多孔Mn 2 O3前体制备LiMnPO 4/C纳米片的新方法。这样做有两个好处。首先，通过负压浸渍，将磷酸二氢锂（LiH 2 PO 4）、氢氧化锂（LiOH）和蔗糖（C12 H22 O 11）沉积在多孔Mn 2 O3纳米片的表面。在随后的固相反应中，三维连续导电碳均匀地包裹在LiMnPO 4/C纳米片周围，大大提高了导电性。其次，使用Mn 2 O3分级微球作为前体获得（010）暴露面，这允许Li+离子的快速传输，从而提高倍率性能。结果，所合成的L-Mn 2 O3-LMP/C样品表现出优异的上级倍率性能，在C/20下的放电容量为157.3 mA h g−1，在1C下的放电容量为122.6 mA h g−1，在2C下的放电容量为105.8 mA h g−1。同时，它们在1C下循环100次后仍能保持99.3%的初始容量，显示出优异的循环稳定性。该方法为高性能LiMnPO 4/C正极材料的制备提供了新的思路，适合于大规模生产。
Preparing high-performance LiMnPO4 is still a large obstacle due to its sluggish electrochemical kinetics. To overcome this problem, a novel method is developed for LiMnPO4/C nanoplates from nanoporous Mn2O3 precursors. There are two advantages. Firstly, through negative pressure immersion, lithium dihydrogen phosphate (LiH2PO4), lithium hydroxide (LiOH) and sucrose (C12H22O11) are deposited on the surface of porous Mn2O3 nanosheets. In the following solid-state reaction, three dimensional continuous conductive carbon is wrapped uniformly around the LiMnPO4/C nanoplates, which greatly improved the conductivity. Secondly, (010) exposed facets are obtained using the Mn2O3 hierarchical microspheres as precursors, which allows for a fast transmission of Li+ ions improving the rate capability. As a result, the as-synthesized L-Mn2O3-LMP/C samples exhibit a superior rate performance with discharge capacities of 157.3 mA h g−1 at C/20, 122.6 mA h g−1 at 1C, and 105.8 mA h g−1 at 2C. Meanwhile, they can retain 99.3% of the initial capacity after 100 cycles at 1C, revealing an excellent cycling stability. This method sheds more light on the fabrication of high-performance LiMnPO4/C cathode materials and is suitable for large scale productions.