Superior Long-Term Energy Retention and Volumetric Energy Density for Li-Rich Cathode Materials
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- 作者：Pilgun Oh ; Seungjun Myeong ; Woongrae Cho ; Min-Joon Lee ; Minseong Ko ; Hu Young Jeong ; Jaephil Cho
- 刊名：Nano Letters
- 出版年：2014
- 出版时间：October 8, 2014
- 年：2014
- 卷：14
- 期：10
- 页码：5965-5972
- 全文大小：603K
- ISSN：1530-6992
文摘
Li-rich materials are considered the most promising for Li-ion battery cathodes, as high energy densities can be achieved. However, because an activation method is lacking for large particles, small particles must be used with large surface areas, a critical drawback that leads to poor long-term energy retention and low volumetric energy densities. Here we propose a new material engineering concept to overcome these difficulties. Our material is designed with 10 渭m-sized secondary particles composed of submicron scaled flake-shaped primary particles that decrease the surface area without sacrificing rate capability. A novel activation method then overcomes the previous limits of Li-rich materials with large particles. As a result, we attained high average voltage and capacity retention in turn yielding excellent energy retention of 93% during 600 cycles. This novel and unique approach may furthermore open the door to new material engineering methods for high-performance cathode materials.