Transition metal-doped Ni-rich layered cathode materials for durable Li-ion batteries

Abstract

Doping is a well-known strategy to enhance the electrochemical energy storage performance of layered cathode materials. Many studies on various dopants have been reported; however, a general relationship between the dopants and their effect on the stability of the positive electrode upon prolonged cell cycling has yet to be established. Here, we explore the impact of the oxidation states of various dopants (i.e., Mg2+, Al3+, Ti4+, Ta5+, and Mo6+) on the electrochemical, morphological, and structural properties of a Ni-rich cathode material (i.e., Li[Ni0.91Co0.09]O2). Galvanostatic cycling measurements in pouch-type Li-ion full cells show that cathodes featuring dopants with high oxidation states significantly outperform their undoped counterparts and the dopants with low oxidation states. In particular, Li-ion pouch cells with Ta5+- and Mo6+-doped Li[Ni0.91Co0.09]O2 cathodes retain about 81.5% of their initial specific capacity after 3000 cycles at 200 mA g−1. Furthermore, physicochemical measurements and analyses suggest substantial differences in the grain geometries and crystal lattice structures of the various cathode materials, which contribute to their widely different battery performances and correlate with the oxidation states of their dopants.

Dynamics of particle network in composite battery cathodes

“…Alleviation of the active particle damage has focused on understanding and tuning the morphological and chemical characteristics at the microscale ( 9 – 12 ), such as particle size, elongation and sphericity ( 13 , 14 ), crystallographic arrangement ( 15 , 16 ), mesoscale kinetics ( 17 , 18 ), grain boundary properties ( 19 , 20 ), and compositional variation ( 21 – 24 ). For instance, reducing the primary particle size is an effective approach to improving the fast-charging performance because smaller particles have shorter ion diffusion paths ( 25 , 26 ).…”

Progress in electrode and electrolyte materials: path to all-solid-state Li-ion batteries

“…Another important strategy is to enhance the electrochemical performance, which is a substitution of cations (Ti, Cu, Ni, Cr, Mn, Mg, Fe, etc. ), anions (F), and doping of mixed elements [241]. This is an alternative for the surface coating or electrode modification to enhance electronic conductivity.…”

“…), anions (F), and doping of mixed elements. 243 This is an alternative to surface coating or electrode modification to enhance the electronic conductivity. The dopant may alter the structure and affect the structural stability and charge compensation.…”

Assessment of the Feasibility of Zn–Air Batteries with Alkaline Electrolytes Working at Sub-Zero Temperatures

“…Lithium-ion batteries are currently the most widely applied energy storage devices. − In general, the temperature has a serious impact on the operation of the battery. For example, the capacity of a lithium-ion battery decays severely at −40 °C, which is only 12% of that at room temperature .…”