Method for preparing nano-lithium titanate cathode material

Abstract

The invention discloses a method for preparing a nano cathode material of a lithium ion battery at a low cost. A basic structural formula of the cathode material of the lithium ion battery is Li4Ti5O12 with a cubical spinel structure. The method is characterized by comprising the following steps of (1) sufficiently mixing a lithium salt precursor, TiO2 and a carbon precursor in a water, aqueous solution or solvent environment to obtain a precursor suspension; (2) grinding the precursor suspension; (3) drying the precursor suspension to obtain a precursor mixture; (4) carrying out calcinations on the precursor mixture in an inert atmosphere or inert and air atmosphere; and (5) smashing and grading the clacinated product to obtain a Li4Ti5O12 cathode material or Li4Ti5O12 / C composite cathode material. The Li4Ti5O12 cathode material and the Li4Ti5O12 / C composite cathode material have excellent electrochemical performance. The invention also provides a nano-electrochemically active cathode material with low cost and uniform particle size distribution produced by the method, and electrodes and batteries manufactured by the nano-electrochemically active cathode material.

Description

technical field [0001] The invention relates to the field of electrochemical rechargeable batteries, in particular to a method for preparing a non-carbon negative electrode composite material of a lithium ion battery, and a corresponding electrode and battery. Background technique [0002] Since the commercialization of lithium-ion battery products by Sony in the 1990s, it is different from traditional lead-acid, nickel-cadmium, nickel-metal hydride and other batteries in terms of electrochemical charging and discharging mechanism and higher volume specific energy and weight specific energy. And good environmental protection quickly penetrates into various application fields. The principle of repeated charging and discharging of lithium-ion batteries is not limited to the electrochemical reaction between a specific positive electrode and negative electrode materials. Its positive electrode or negative electrode materials can be paired in a variety of options to meet the need...

AI Technical Summary

Problems solved by technology

However, graphite carbon has the following obvious shortcomings as the negative electrode of lithium-ion batteries: (1) In order to ensure the long life of the battery charge and discharge, the surface of the graphite carbon negative electrode inevitably consumes Li+ during the initial charge and discharge process and reacts with the electrolyte to form a A solid-electrolyte interface film (SEI), this process produces a certain irreversible capacity, and the SEI film will continue to consume more Li+ if it changes or even breaks with the cycle, causing the capacity to decay and lifespan to decrease; more serious cases Yes, in some carbon graphite negative electrodes, due to the insertion of some products of the SEI film into the graphite carbon side planar structure, the negative electrode structure collapses and the battery cannot be charged and discharged normally, which limits some excellent electrolyte solvents such as PC, etc. Applications

(2) Graphite carbon will have a volume change of about 10% during charging and discharging. This change will lead to separation between active materials, and the pole piece will lose the continuity of electronic conduction. Ultimately, the life of the battery will be shortened and the safety will be reduced.

Another synthetic method is the sol-gel method (US7368097B2, EP1282180A1, EP1412993A1, Y.H.Rho, et al., J.Electrochem.Soc.151(2004)A106.), which is characterized in that the soluble compound precursor containing titanium and lithium The solid dissolves in the solvent and undergoes a homogeneous reaction, so it can be mixed at the molecular level to produce a product with good uniformity. However, the process involves the use of organometallic reactant precursors and organic solvents, which greatly increases the cost of raw materials. In addition, The manufacturing process is complicated, so it is difficult to achieve large-scale industrial production

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