Nano coating of negative electrode materials and preparation method of secondary aluminium cell using negative electrode materials

Abstract

The invention discloses a novel high-energy secondary aluminium cell and a preparation method. The aim is to provide a method for preparing nano material-coated negative electrode active materials, by coating the negative electrode active materials with the nano materials, it is possible to subject the negative electrode active materials to nano treatment; therefore, the high-energy secondary aluminium cell features obviously improved properties, simple material composition, low cost, simple technology, environmentally friendly synthesis path, relatively high charge-discharge capacity and relatively good cycle property and market prospect. The aluminium cell comprises the positive and negative electrodes in the modified positive and negative electrode active materials coated by the nano material surfaces or any one electrode in the singly coated positive or negative electrode active materials, polyelectrolyte (ionic liquid) and a diaphragm. The coating materials are semimetals, oxides, salts or conductive polymers. The invention uses the nano materials in the secondary aluminium cell for the first time; therefore, the cell has higher open circuit voltage and reversible capacity and better cycle property, can be applied to such fields as portable power sources like mobile telephones, notebooks and portable electronic components, and as electric vehicles, hybrid electric vehicles and the like, and has broad application and development prospects.

Description

technical field [0001] The present invention relates to a preparation method of a nano-coated negative electrode active material, and a secondary aluminum battery and a preparation method thereof, more specifically, to a preparation method of a nano-coated negative electrode active material, positive and negative nano double-coated A secondary aluminum battery with active materials and a preparation method thereof, or a secondary aluminum battery with nano single-coated positive and negative active materials and a preparation method thereof. Background technique [0002] With people's thirst for high-energy-density power sources, there is an urgent need for the development and application of cheap, safe, environmentally friendly and high-performance secondary batteries. A secondary aluminum-sulfur battery that uses aluminum and its alloys as the negative electrode material and chalcogenide materials as the positive electrode is one of the batteries that meet the above requir...

AI Technical Summary

Problems solved by technology

However, primary aluminum batteries represented by aluminum-air batteries cannot be recharged and cannot be recycled because the electrolyte system is an aqueous solution.

[0004] There are many forms of sulfur. Elemental sulfur is an insulator of ions and electrons at room temperature. The small molecular organic sulfides produced when the sulfur-sulfur bond is broken are dissolved in the electrolyte to form disordered sulfur with irreversible reactions, resulting in rapid self-discharge and capacity. Attenuation and other issues, so that the cycle performance of the battery will soon decline

[0005] In order to avoid the above problems and endow the battery with excellent performance, Naoi first synthesized the dithiodianiline polymer positive electrode material (J. Electrochem. Soc., 1997, 144 (6): L173) in 1997 and applied it in the lithium battery system However, it is difficult to obtain practical application because the preparation raw materials of this type of material are expensive and the synthesis process is complex; US5441831, 5460905, 5601947 and 5609720 disclose carbon-sulfur compounds, but they have low theoretical capacity problem, and it is not easy to regenerate materials with the same molecular structure; Skothcim applied polycarbon disulfide (PCS) electrodes to secondary lithium batteries and obtained better capacity and cycle performance (US Patent, 5460905), but the synthesis process Environmental pollution cannot be ignored; Wang Jiulin used the method of high-temperature dehydrogenation to achieve branched cross-linking of S-S structure on polyethylene oxide, polyvinylidene fluoride and other polymer substrates (CN1339839A). Corrosive gases have a great impact on the environment and equipment, so there are certain defects in this synthesis route

[0006] Aluminum as a negative electrode material also has some problems that cannot be ignored: (1) the actual working potential of aluminum is much higher than the theoretical value; there is a strong affinity between aluminum alloy and oxygen, in air and aqueous solution, the surface generates a The dense passivation oxide film makes the electrode potential of aluminum not reach the proper theoretical electrode potential, and also causes voltage hysteresis during discharge.

(2) Aluminum is a typical amphoteric metal with high activity and is easy to react with acid and alkali to destroy the oxide film. Once the oxide film is destroyed, it will be corroded quickly