Details

Autor(en) / Beteiligte

• Wu, Zhongzhen
• Ji, Shunping
• Hu, Zongxiang
• Zheng, Jiaxin
• Xiao, Shu
• Lin, Yuan
• Xu, Kang
• Amine, Khalil
• Pan, Feng

Titel

Pre-Lithiation of Li(Ni1‑x‑y Mn x Co y )O2 Materials Enabling Enhancement of Performance for Li-Ion Battery

Ist Teil von

• ACS applied materials & interfaces, 2016-06, Vol.8 (24), p.15361-15368

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Transition metal oxide materials Li­(Ni x Mn y Co z )­O2 (NMCxyz) based on layered structure are potential cathode candidates for automotive Li-ion batteries because of their high specific capacities and operating potentials. However, the actual usable capacity, cycling stability, and first-cycle Coulombic efficiency remain far from practical. Previously, we reported a combined strategy consisting of depolarization with embedded carbon nanotube (CNT) and activation through pre-lithiation of the NMC host, which significantly improved the reversible capacity and cycling stability of NMC532-based material. In the present work we attempt to understand how pre-lithiation leads to these improvements on an atomic level with experimental investigation and ab initio calculations. By lithiating a series of NMC materials with varying chemical compositions prepared via a conventional approach, we identified the Ni in the NMC lattice as the component responsible for accommodating a double-layered Li structure. Specifically, much better improvements in the cycling stability and capacity can be achieved with the NMC lattices populated with Ni3+ than those populated with only Ni2+. Using the XRD we also found that the emergence of a double-layer Li structure is not only reversible during the pre-lithiation and the following delithiation, but also stable against elevated temperatures up to 320 °C. These new findings regarding the mechanism of pre-lithiation as well as how it affects the reversibility and stability of NMC-based cathode materials prepared by the conventional slurry approach will promote the possibility of their application in the future battery industry.