A high-capacity Li[Ni0.8Co0.06Mn0.14]O-2 positive electrode with a dual concentration gradient for next-generation lithium-ion batteries

作者：Park Kang Joon; Lim Byung Beom; Choi Moon Ho; Jung Hun Gi; Sun Yang Kook^*; Haro Marta; Vicente Nuria; Bisquert Juan; Garcia Belmonte Germa

来源：Journal of Materials Chemistry A, 2015, 3(44): 22183-22190.

DOI：10.1039/c5ta05657h

To increase the reversible capacity of layered lithium nickel-cobalt-manganese oxide, a Li [Ni0.8Co0.06Mn0.14]O-2 positive electrode with a two-sloped full concentration gradient (TSFCG) was successfully synthesized via co-precipitation. The TSFCG maximizes the Ni concentration in the particle core and the Mn concentration on the particle surface. The TSFCG Li[Ni0.8Co0.06Mn0.14]O-2 positive electrode showed improved overall electrochemical properties (i.e., reversible capacity, cycle life, and rate capability) and thermal stability compared to a conventional positive electrode (CC) Li [Ni0.8Co0.06Mn0.14]O-2 without a concentration gradient. Electrochemical impedance spectroscopy showed that the high stability of the outer surface composition of Li[Ni0.64Co0.06Mn0.30]O-2 is responsible for reduction in surface resistance and charge transfer resistance by decreasing the parasitic reaction with the electrolyte. These reduced resistances explain the superior rate capability of TSFCG positive electrodes.

• 出版日期2015