Comparative studies of the electrochemical performance of Lithium-Rich materials (Li1.2Ni0.2Mn0.6O2)?

AUGUSTO RODRÍGUEZ; MIGUEL A. SANSERVINO; GÓMEZ SOFÍA; M. G. ORTIZ,; VISINTIN A.

Cochabamba

Congreso; International Workshop od Lithium Industrial Minerals and Energy (IWLIME 2021).; 2021

International Workshop od Lithium Industrial Minerals and Energy (IWLIME).

Manganese based Lithium-Rich materials represent a group of laminar compounds with promising characteristics that could be protagonist for development of a new generation of rechargeable Li-ion batteries. These materials could deliver high discharge capacities and high energy densities which are enough for fulfill the requirements of electric cars and devices used to storage energy coming from more clean and renewable sources. However, some disadvantages still remain unsolved preventing their commercial or industrial use [1]; like a rapid discharge capacity and voltage fade. In order to further understand the mechanics behind this process, two Lithium Rich materials, both with a composition of Li1.2Ni0.2Mn0.6O2, were synthetized; one through co-precipitation method (LiR-COP) [2] and the other through a simple, one step, solid state reaction method (LiR-SSR) [3]. The LiR-COP material showed a well-defined activation of the Li2MnO3 phasein the form of an intense peak in the cyclic voltammetry studies and a longer plateau in the first cycle charge profile (Figure 1.a) and 1.c). This phenomenon is apparently responsible for the higher discharge capacity (200 mAh g-1) during the first 40 galvanostatic charge-discharge cycles; on the other hand, this irreversible phase activation is also partially responsible for the capacity fade in comparison with the LiR-SSR material (Figure 1. d). Both materials showed an average discharge potential of 3.5±0.1V through the first 10 charge-discharge cycles (Figure 1.b). The results exhibited how the synthesis method greatly influence in the electrochemical properties and how could these procedures be adjusted to get one step closer to the synthesis of a Li-Rich materials with a better cycling performance.