Solution combustion synthesis of LiMn2O4 fine powders for lithium ion batteries

Abstract

In this work, fine powders of spinel-type LiMn 2 O 4 as cathode materials for lithium ion batteries (LIBs) were produced by a facile solution combustion synthesis using glycine as fuel and metal nitrates as oxidizers. Single phase of LiMn 2 O 4 products were successfully prepared by SCS with a subsequent calcination treatment at 600 to 1000 ºC. The structure and morphology of the powders were studied in detail by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical properties were characterized by galvanostatic charge-discharge cycling and cyclic voltammetry. The crystallinity, morphology, and size of the products were greatly influenced by the calcination temperature. The sample calcined at 900 ºC had good crystallinity and particle sizes between 500 and 1000 nm. It showed the best performance with an initial discharge capacity of 115.6 mAh g -1 and a capacity retention of 93% after 50 cycles at a 1 C rate. In comparison, the LiMn 2 O 4 sample prepared by the solid-state reaction showed a lower capacity of around 80 mAh g -1 .

Surfactant-assisted synthesis of Sn nanoparticles via solution plasma technique

“…The electrochemical characterizations were carried out in two-electrode Swagelok-type cells 24,25 Figure 1 shows the XRD patterns of the different samples (Sn-NPs) prepared with various concentrations of CTAB. Figure 2 shows the corresponding microstructural analysis performed using SEM.…”

“…Actual surface area will be increased due to surface roughness of particles and existence of colloidal SnO2 nanoparticles shown in Fig.3 (c) with the particle size less than 10 nm. According to the literature 25 , the adsorption area of one CTAB molecule is 0.35 nm 2 .…”

Optimized conditions for glycine-nitrate-based solution combustion synthesis of LiNi0.5Mn1.5O4 as a high-voltage cathode material for lithium-ion batteries

“…The as-derived sol-gels in the crucibles were transferred to a lab-made combustion synthesis apparatus [14,15], shown in Figure 1. The reactor was transferred to a heater which was pre-heated to and maintained at 400 ºC.…”

“…The electrochemical performance of the cathode materials were studied using a two-electrode Swagelok-type cell with a lithium metal anode as described in previous studies [14,16]. The working electrodes consisted of the active oxide material, conductive carbon (acetylene black), and polymer binder (polyvinylidene fluoride, PVDF) in a weight ratio of 8:1:1.…”

“…This method not only yields nanosized products exhibiting large specific surface areas but also enables a uniform (homogeneous) doping of trace amounts of various elements in a single step. Several reports have been concerned with the solution combustion synthesis of cathode materials for LIBs, such as the glycine-based combustion synthesis of layered LiMO 2 and spinel-type LiMn 2 O 4 [12][13][14]. The characteristics (including purity, structure, and size) of the SCS-derived oxides are typically determined by several synthetic parameters, such as the species of fuel and oxidizer reactants, the fuel-to-oxidizer ratio, and the subsequent sintering treatment after SCS.…”