A green recycling process designed for LiFePO4 cathode materials for Li-ion batteries
A green recycling process designed for LiFePO4 cathode materials for Li-ion batteries
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DOI：
10.1039/c5ta02540k
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发表时间：
2015-05
影响因子：
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通讯作者：
Eun Jeong Shin;S. Kim;Jae-Kyo Noh;D. Byun;K. Chung;H. Kim;B. Cho
中科院分区：
文献类型：
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作者：
Eun Jeong Shin;S. Kim;Jae-Kyo Noh;D. Byun;K. Chung;H. Kim;B. Cho
提出了一种绿色的LiFePO 4/C电极材料回收工艺路线。首先，提出了从结晶FePO 4·2 H2O相（偏磷酸铁I）的前体合成LiFePO 4/C正极材料的稳健策略。为了制备结晶FePO 4·2 H2O，采用溶液沉淀路线，其中反应条件如温度和pH精确控制。在不同的热处理温度下制备的FePO 4·2 H2O与锂源的混合物中，我们发现在700 °C下合成的LiFePO 4/C正极材料在0.1 C下的最大放电容量为168.51 mA h g−1（1 C倍率= 170 mA h g−1），在1 C下25次循环后的容量保持率为99.36%。此外，商业上可获得的LiFePO 4粉末和从废旧电池中回收的LiFePO 4电极材料都使用我们开发的回收工艺进行了测试，其中我们分解LiFePO 4粉末/电极以制备结晶FePO 4·2 H2O，然后重新合成LiFePO 4/C正极材料。在这两种情况下，我们回收的LiFePO 4/C在1 C下的放电容量均为140 mA h g−1，容量保持率为99%。
A green process route to recycle LiFePO4/C electrode materials is proposed in this work. First, a robust strategy to synthesize LiFePO4/C cathode materials from a precursor of a crystalline FePO4·2H2O phase (metastrengite I) is presented. In order to prepare crystalline FePO4·2H2O, a solution precipitation route is adapted, where the reaction conditions such as temperature and pH are precisely controlled. Among various heat treatment temperatures to calcine our prepared FePO4·2H2O with lithium sources, we find that LiFePO4/C cathode materials synthesized at 700 °C deliver a maximum discharge capacity of 168.51 mA h g−1 at 0.1 C (1 C rate = 170 mA h g−1) with a capacity retention of 99.36% after the 25th cycle at 1 C. Furthermore, commercially available LiFePO4 powders and recovered LiFePO4 electrode materials from spent batteries are both tested with our developed recycling process, where we decompose LiFePO4 powders/electrodes to prepare crystalline FePO4·2H2O, and then re-synthesize LiFePO4/C cathode materials. In both cases, our recycled LiFePO4/C exhibits a very comparable discharge capacity of ∼140 mA h g−1 at 1 C with a capacity retention of ∼99%.