title: Superior long-term energy retention and volumetric energy density for Li-rich cathode materials.
abstract: 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 μm-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.
authors.affiliation: Department of Energy Engineering, School of Energy and Chemical Engineering and ‡UNIST Central Research Facilities (UCRF), Ulsan National Institute of Science and Technology (UNIST) , 689-798, Ulsan, South Korea.
authors.forename: Pilgun
authors.initials: P
authors.lastname: Oh
authors.forename: Seungjun
authors.initials: S
authors.lastname: Myeong
authors.forename: Woongrae
authors.initials: W
authors.lastname: Cho
authors.forename: Min-Joon
authors.initials: MJ
authors.lastname: Lee
authors.forename: Minseong
authors.initials: M
authors.lastname: Ko
authors.forename: Hu Young
authors.initials: HY
authors.lastname: Jeong
authors.forename: Jaephil
authors.initials: J
authors.lastname: Cho
keywords: Li-rich; Lithium-ion battery; chemical treatment; long-term cycling; material design