Secondary aluminum battery and preparation method of positive electrode thereof

Abstract

The invention discloses a secondary aluminum battery and a preparation method of anode thereof; the secondary aluminum battery comprises a battery anode, a battery cathode, an electrolyte, a diaphragm and a current collector; the battery cathode is made of aluminum or aluminum alloy; the battery anode is made of polystyrene polysulfide or carbonyl sulfide composite material; and the electrolyte is halogen aluminic acid ionic liquid. The preparation method of secondary aluminum battery anode material (polystyrene polysulfide) comprises the following steps: (1) preparing chlorination polystyrene; (2) preparing polystyrene polysulfide; (3) slowly dropping sodium polysulfide solution into chlorination polystyrene solution according to the proportion of Na to C1 being 1: 1 at the temperature of 50 to 150 DEG C, stirring so as to react about 24 hours. Powder product is obtained after cleaning and extracting to obtain polystyrene polysulfide product dried about 24 hours in vacuum at the temperature of 80 DEG C.

Description

technical field [0001] The invention relates to a secondary aluminum battery and a method for preparing a positive electrode thereof. Background technique [0002] The rapid development of new power sources such as smaller, lighter and higher-performance electronic and communication equipment, electric vehicles, and wind power generation, photovoltaic power generation, etc., has put forward higher and higher requirements for the battery performance of the supporting power supply. Currently commercialized lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries and lithium-ion batteries can no longer meet these requirements. There is an urgent need to develop power batteries and energy storage batteries with the characteristics of high energy, low cost, long life, green environmental protection, abundant battery material resources, and recyclable utilization. Secondary aluminum-sulfur batteries with aluminum metal or aluminum alloys as negative electrode...

AI Technical Summary

Problems solved by technology

This is because of many problems that aluminum electrodes will produce in aqueous electrolytes: (1) There is a strong affinity between aluminum alloys and oxygen. In air and aqueous solutions, a dense passivation oxide film is formed on the surface, making aluminum The electrode potential in the neutral solution does not reach the theoretical electrode potential, and the actual working potential of aluminum is much lower than the theoretical value, which 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, which makes the utilization rate of the electrode low and the wet storage performance is low. Difference

(3) Aluminum has a large self-corrosion in alkaline solution, and it is prone to serious hydrogen evolution reaction with the medium, which reduces the utilization rate of the electrode and affects the normal operation of the battery

(4) In alkaline medium, the products of aluminum anode flow reaction and corrosion reaction are colloidal Al(OH) 3 , not only reduces the conductivity of the electrolyte but also increases the polarization of the aluminum anode, which deteriorates the performance of the aluminum battery

The polysulfides formed during discharge of lithium / sulfur batteries are easily soluble in the electrolyte, causing self-discharge and blocking the diaphragm. During charging, it is easy to form a passivation layer on the surface of the positive electrode active material, making it difficult for ions and electrons to migrate, thereby The specific capacity of the battery is reduced and the cycle life is very poor

[0009] However, this positive electrode material still has many shortcomings, which restrict the practical application of lithium / sulfur batteries: first, the electrical insulation of elemental sulfur leads to low utilization of active materials; The sulfide dissolves in the electrolyte and generates irreversible disordered sulfur, which causes the battery to self-discharge, increases the viscosity of the electrolyte, hinders ion diffusion, and the distribution of active substances in the electrode changes greatly, which may occur after many cycles The agglomeration phenomenon causes the capacity to decay rapidly and the cycle performance of the battery to decline rapidly