TiO₂ was coated on the surface of LiMn₂O₄ by thermal decomposition of titanate coupling agent, and the effects of coating treatment on the structure and electrochemical performance of LiMn₂O₄, as well as material structure in the cycling were all explored. The results show that TiO₂ can be uniformly coated on the surface of the LiMn₂O₄ by thermal decomposition of titanate coupling agent at 550 ℃. Surface coating does not change the crystal structure of LiMn₂O₄, but obviously improves its electrochemical performance, especially high temperature rate performance and cycle performance. At 55 ℃, LiMn₂O₄ with TiO₂ coating delivers a specific capacity of 75.34 mAh/g at 5C, which is higher than that without coating (43.05 mAh/g). After 150 cycles, the capacity retention rate of the material with TiO₂ coating and without coating is 77.27% and 62.85%, respectively. The improvement of electrochemical performance is attributed to reduction of Mn dissolution in the cathode material by TiO₂ coating, which thus inhibits the change of crystal structure during cycling process, reduces the electrode polarization and charge transfer impedance, as well as improves the charge-discharge reversibility of the material and the Li⁺ diffusion.

LiMn_0.6Fe_0.4PO₄/C (LMFP) composite synthesized by a combined process of co-precipitation and solid-phase sintering not only has low impurity content, uniform phase distribution, but also exhibits excellent electrochemical performance. It is shown that such process can inhibit the formation of Mn₂P₂O₇ phase and improve the lithium ion diffusion rate of LMFP, while removing NH₄⁺ and H₂O. The Li-ion batteries assembled with LiMn_0.6Fe_0.4PO₄/C exhibit excellent electrochemical performance, showing initial specific discharge capacity of 145.5 mAh/g at 1C and 111.9 mAh/g at 5C. It is concluded that this process, being simple and cost-effective, is suitable for industrial production. Such study provides a feasible scheme in designing cathode materials for commercialized high-performance Li-ion batteries.

With manganese sulfate as raw material and hexadecyl trimethyl ammonium bromide as modifier, trimanganese tetroxide was synthesized by complex-precipitation method, with which lithium manganate cathode material was then synthesized by high-temperature solid-state reaction. The effects of modifier amount on the morphology and particle size of trimanganese tetroxide and the specific discharge capacity of lithium manganate cathode material were all discussed. Results show that serious particle agglomeration can occur in the trimanganese tetroxide synthesized without modifier. With 3.0 g/L hexadecyl trimethyl ammonium bromide as the modifier, the synthesized trimanganese tetroxide has uniform particle size, and is dispersed without any agglomeration. Spinel lithium manganate was synthesized with the self-made modified trimanganese tetroxide, and then compared with the spinel lithium manganate synthesized with three kinds of trimanganese tetroxide available on the market. The results show that the lithium manganate synthesized with the self-made modified trimanganese tetroxide can present better electrochemical performance, delivering an initial discharge capacity of 120.43 mAh/g, with a retention rate of 96.79% after 50 cycles at 1C.

With an increase in Ni content, the capacity of high-nickel layered metal oxides (LiNi_xMn_yCo_1-x-yO₂ (0.8≤x<1, NCM) greatly decreases. In view of such problem, it is proposed that singly-crystal NCM cathode material be modified by dual SiO₂@Li₂SiO₃ coating to improve its electrochemical performance. During the synthesis process, the reaction of can consume the residue lithium on the material surface, thus improving diffusion kinetics of interface lithium ions and inhibiting side reaction at the interface. It is shown that the modified cathode material delivers a specific discharge capacity of 156.88 mAh/g after 120 cycles, with capacity retention rate of 70.52%.

With vanadium pentoxide and citric acid as raw materials, a kind of 3D flower-like VO₂(B) electrode material with large specific surface area and excellent structural stability was prepared by adopting hydrothermal synthesis. The crystal structure and morphology of the VO₂(B) electrode material were characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscope, and the electrochemical properties of VO₂(B) electrode material were measured by constant current charge and discharge, as well as cyclic voltammetry. The results show that the first specific dischage capacity of 3D flower-like VO₂(B) electrode material is 227 mAh/g at a current density of 0.1 A/g. It delivers the first specific discharge capacity of 151 mAh/g at a high current density of 1 A/g, and retains 79.6% of this capacity after 300 charge-discharge cycles, exhibiting a good rate performance.

An overview of progress in the research on anode materials of lithium-ion batteries based on vanadium-based compounds (including vanadium oxide, vanadate, vanadate phosphate and oxide-free vanadium-based compounds) is presented. Furthermore, based on the analysis of relationship among modification method and structure of material and electrochemical performance, it is proposed that vanadium-based anode materials for lithium-ion batteries shall become the trend in the future research.

With silicon material (BFSi) extracted from blast furnace slag as silicon source and polyacrylonitrile (PAN) as carbon source, a kind of silicon-carbon anode material for lithium-ion batteries was synthesized. And the influence of ratio of silicon to polyacrylonitrile on the BFSi@C material was investigated. Results show that BFSi@C synthesized with BFSi and PAN in a mass ratio of 3∶1 delivers an initial charge capacity of 1 884.99 mAh/g at a current density of 0.5 A/g. After 100 cycles, it still delivers a specific charge capacity of 1 509.32 mAh/g, with a capacity retention rate of 80.07%. Moreover, it presents excellent rate performance at high current densities. Compared with commercial silicon materials, BFSi@C demonstrates higher cycle capacity and superior rate performance, delivering a specific capacity up to 538.31 mAh/g at a current density of 5 A/g.

Sn-Sb-Cu-Fe-Zn high-entropy alloy nanoparticles were uniformly anchored on conductive interconnected carbon nanofibers by electrospinning in combination with calcination process, and a composite anode material of SnSbCuFeZn@CNFs for lithium-ion batteries was successfully synthesized. Research shows that calcination temperature has an important influence on the phase composition and morphology characteristics of the synthesized material, and directly affects the crystal phase, size and distribution of Sn-Sb-Cu-Fe-Zn high-entropy alloy nanoparticles, also determines the electrochemical performance of SnSbCuFeZn@CNFs electrode. In the studied samples, the SnSbCuFeZn@CNFs-900 electrode can present excellent comprehensive performance: it delivers an initial specific discharge capacity of 1 232.8 mA/g at 0.1 A/g, and has reversible specific discharge capacity retaining at 786.0 mA/g after 200 cycles; it delivers a specific discharge capacity of 433.8 mA/g after 500 cycles at 1.0 A/g; it is found that the pseudo-capacitance accounts for as high as 93.37% at a scanning speed of 2.0 mV/s.

With tetraethyl orthosilicate as silicon source and cetyltrimethylammonium bromide (CTAB) as a surfactant and pore-forming agent, a carbon-coated mesoporous hollow silicon oxide as anode material was synthesized by adopting the modified stöber method and carbonthermal reduction. The results show that different volume ratio of ethanol to water can bring important impact to the particle size, morphology and performance of SiO_x nanospheres. With ethanol and water in a low volume ratio, the obtained nanomaterial has a low sphericity and becomes oval; as the ratio increases, the nanomaterial becomes larger in size; with ethanol and water in a ratio of 0.45, the obtained SiO_x nanospheres are around 300 mm in size. The button batteries assembled with such nanospheres deliver a reversible specific capacity of 813 mAh/g after 200 cycles at a current density of 100 mA/g, and 704 mAh/g after 1 200 cycles at 500 mA/g, retaining 82% of this capacity, with a capacity attenuation rate of 0.015% after each cycle.

The influence of polyether additives on performance of ultra-thin Li-ion battery copper foil with thickness of 5 μm was studied by electrochemistry, scanning electron microscopy, and X-ray diffractometer. The results show that addition of polyether additives into electrolyte can promote negative shift of Cu deposition potential, and polyether additives with suitable concentration can lead to finer grains of copper foil, which is conducive to improving the surface flatness of copper foil. When the mass concentration of polyether additives is 2.3 mg/L, the obtained copper foil has tensile strength of 620.43 MPa, elongation of 3.67%, glossiness of 161 GU, and surface roughness of 1.02 μm, presenting excellent overall performance. The electrolytic copper foil with high tensile strength has a preferred orientation of (111) plane.