Production method for tin-copper-cobalt ternary alloy cathode material of lithium ion battery

Abstract

The present invention discloses a preparation method of lithium-ion battery by Sn-Cu-Co alloy negative-pole materials, pertaining to the art of lithium-ion battery technology. The method is a carbon thermal reduction method to calculate the amount of Sn, Cu and Co oxides according to the Sn / (Cu+Co) atomic ratio of 3:1-2:3; wherein, the atomic ratio of Cu / Co is 5:1-1:5; the amount of carbon powder is calculated in terms of CO which is reduced from the oxygen in all oxides. After being evenly mixed and ground, the raw material is placed in a flowing protection atmosphere so as to rise to the required target temperature at a heating rate of 2-30 DEG C per minute and after a certain time of insulation, the temperature of the raw material declines to the room temperature with the cooling of furnace. The present invention has the advantages of low material cost, simple preparation process, less time consumption, high yield, good safety, great application value in material preparation and suitability for mass production. The Sn-Cu-Co alloy has the advantages that crystallization is higher; the inside is full of micron particles in a loose structure with a smaller surface, which are difficult to reunite in the electrode cycling process; the existence of the two non-active components Cu and Co greatly releases the volume changes in the electrode cycling process and is conducive to enhancing the stability of the electrode cycling.

Description

technical field [0001] The invention relates to a lithium ion battery negative electrode material, in particular to a preparation technology for preparing a lithium ion battery tin-copper-cobalt alloy negative electrode material by a carbothermal reduction method. Background technique [0002] Lithium-ion batteries are one of the high-energy batteries that can best meet the sustainable development requirements of the future society, but the capacity of its electrode materials has not been greatly improved, thus restricting the rapid development of high-energy lithium-ion batteries. At present, most commercial lithium-ion batteries use graphite materials as negative electrodes. The theoretical mass specific capacity of graphite carbon materials is 372mAh / g, and the volume specific capacity is 800mAh / mL. After people's continuous improvement, the actual carbon materials are now The specific capacity is very close to its theoretical specific capacity, so the potential for furth...

AI Technical Summary

Problems solved by technology

At present, the main problem that hinders the commercialization of Sn-based alloy anode materials is that during the process of lithium ion intercalation and extraction, the volume change rate of the material is very large, which easily leads to the destruction of the structure of the alloy anode, thereby affecting the charge-discharge cycle stability of the electrode.

In this material, due to the existence of two active components, Sn and Sb, to participate in the electrode reaction, the volume expansion of the electrode is more obvious during the process of lithium intercalation and deintercalation, so the cycle stability is not ideal, especially after multiple cycles. protrude

At present, the preparation of ternary alloy system is mostly prepared by mechanical alloying method, liquid phase chemical reduction method, electrochemical deposition method, etc. These methods are either high in raw material cost, complicated in preparation process, or low in yield, and are not easy to scale up.

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