Multiscale Computational Model for Particle Size Evolution during Coprecipitation of Li-Ion Battery Cathode Precursors

Abstract

Next generation lithium ion batteries require higher energy and power density, which can be achieved by tailoring the cathode particle morphology, such as particle size, size distribution, and internal porosity. All these morphological features are determined during the cathode synthesis process, which consists of two steps, (i) coprecipitation and (ii) calcination. Transition metal hydroxide precursors are synthesized during the coprecipitation process, whereas their oxidation and lithiation occur during calcination. The size and size distribution of crystalline primary and aggregated secondary particles and their internal porosity are determined during coprecipitation. Operating conditions of the chemical reactor, such as solution pH, ammonia concentration, and stirring speed control the final morphological features. Here, a multiscale computational model has been developed to capture the nucleation and growth of crystalline primary particles and their aggregation into secondary transition metal hydroxide precursor particles. The simulations indicate that increasing solution pH and decreasing ammonia concentration lead to smaller sizes of the secondary particles. A phase map has been developed that can help identify the synthesis conditions needed for a specified particle size and size distribution.

Effect of Particle Size and Doping on the Electrochemical Characteristics of Ca-doped LiCoO₂ Cathodes

“…This signifies that the mechano-chemical route (e.g., high-energy ball milling) could provide a smaller and more evenly distributed particle size distribution with less agglomeration compared to wet-chemical routes, such as co-precipitation. The nucleation and growth of the coprecipitated precursors are determined by various factors such as feeding rate, concentration of solutions, stirring rate, and reactor volume [33]. We speculate that the growth of the precursors were particularly preferred by the experimental condition of coprecipitation in this work.…”

High Performance Nickel Based Electrodes in State-of-the-Art Lithium-Ion Batteries: Morphological Perspectives

“…The secondary particles of a Ni-rich cathode material consist of agglomerated primary particles that form a larger and denser particle. Secondary particle formation reduces the high surface area of primary particles if they are present in singular particles (Barai et al, 2019). The reduction was proven efficient in hindering unwanted reactions between the active materials with the electrolyte (Qiu et al, 2017b;Yudha et al, 2019).…”

Multiscale factors in designing alkali-ion (Li, Na, and K) transition metal inorganic compounds for next-generation rechargeable batteries

“…This method not only provides clues to the unpredictable phenomena, but also derives important key information, which has a positive effect on development of rechargeable batteries. [12][13][14][15][16][17][18] In the case of the formulation and manufacturing of composite electrodes at the industrial level are also an important topic. Regarding this, there are already some insightful review papers on this topic specifically for the Li-ion batteries.…”