Accelerated discovery of cathode materials with prolonged cycle life for lithium-ion battery
Accelerated discovery of cathode materials with prolonged cycle life for lithium-ion battery
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DOI：
10.1038/ncomms5553
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发表时间：
2014-08-01
影响因子：
16.6
通讯作者：
Tanaka, Isao
中科院分区：
文献类型：
--
作者：
Nishijima, Motoaki;Ootani, Takuya;Tanaka, Isao
大规模电池系统对于有效利用太阳能和风能等只能间歇性发电的可再生能源至关重要。使用锂离子电池来储存产生的能量是一种解决方案。在这些应用中使用时，长循环寿命对锂离子电池至关重要;这与最多需要1，000次循环的便携式设备不同。在这里，我们展示了一种新型的共取代磷酸铁锂阴极，估计70%的容量保持率为25，000次循环。这是通过使用密度泛函理论计算探索宽的化学组成空间发现的。化合物在完全锂化和脱锂化条件之间的相对体积变化用作循环寿命的描述符。在筛选结果的基础上，有针对性地合成了所选材料。具有所需的化学组成的单相样品成功地由环氧介导的溶胶-凝胶法。优化后的材料作为锂离子电池负极具有优异的循环寿命性能。
Large-scale battery systems are essential for efficiently utilizing renewable energy power sources from solar and wind, which can generate electricity only intermittently. The use of lithium-ion batteries to store the generated energy is one solution. A long cycle life is critical for lithium-ion battery when used in these applications; this is different from portable devices which require 1,000 cycles at most. Here we demonstrate a novel co-substituted lithium iron phosphate cathode with estimated 70%-capacity retention of 25,000 cycles. This is found by exploring a wide chemical compositional space using density functional theory calculations. Relative volume change of a compound between fully lithiated and delithiated conditions is used as the descriptor for the cycle life. On the basis of the results of the screening, synthesis of selected materials is targeted. Single-phase samples with the required chemical composition are successfully made by an epoxide-mediated sol-gel method. The optimized materials show excellent cycle-life performance as lithium-ion battery cathodes.