Deeper Understanding of the Lithiation Reaction during the Synthesis of LiNiO<sub>2</sub> Towards an Increased Production Throughput
Philipp Kurzhals, Felix Riewald, Matteo Bianchini, Shamail Ahmed, Andreas Michael Kern, Felix Walther, Heino Sommer, Kerstin Volz, Jürgen Janek
Abstract
Efficient manufacturing of cathode active materials (CAMs) for Li-ion batteries is one key target on the roadmap towards cost reduction and improved sustainability. This work deals with a two-stage calcination process for the synthesis of LiNiO 2 (LNO) consisting of a (partial) lithiation step at moderate temperatures and short dwell times and a subsequent high temperature crystallization to decouple the chemical reactions and crystal growth. The use of an agitated-bed lithiation using the rotational movement of a rotary kiln setup shows beneficial effects compared to its fixed-bed counterpart in a crucible as the lithiation reaction is faster under otherwise comparable conditions. The temperature profile for the agitated-bed process was further optimized to avoid the presence of needle-like LiOH residuals in the intermediate product indicative of an incomplete reaction. The partially-lithiated samples were subjected to a second calcination step at a maximum calcination temperature of 700 °C and afterwards revealed comparable physico-chemical properties and electrochemical behavior compared to a reference sample made by a standard one-stage calcination. In a simplified model calculation, the proposed calcination concept leads to an increase in throughput by a factor of ∼ 3 and thus could embody an important lever for the efficiency of future CAM production.