Low-temperature solid-phase synthesis method of nanoscale LiFePO4

Abstract

The invention discloses a low-temperature solid-phase synthesis method of nanoscale LiFePO4 and relates to the technical field of lithium ion battery manufacture. The low-temperature solid-phase synthesis method is characterized in that at least one lithium salt, at least one ferric salt, at least one phosphor salt and at least one carbon source are subjected to ultrafine grinding and then is subjected to low temperature calcination in a non-oxidizing gas protective atmosphere to form the nanoscale LiFePO4. The low-temperature solid-phase synthesis method reduces a calcination temperature and shortens heat preservation time thereby reducing solid-phase reaction energy consumption, maintaining LiFePO4 activity and improving a yield and performance consistence of LiFePO4. The nanoscale LiFePO4 obtained by the low-temperature solid-phase synthesis method has good charge-discharge properties and a high gram volume more than 150mAh / g.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery manufacturing, in particular to the positive electrode material for lithium-ion secondary batteries—LiFePO 4 synthetic method. Background technique [0002] At present, commercial lithium-ion batteries basically use layered lithium cobalt oxide as the positive electrode material. The disadvantages are: 1. The actual capacity is low, at 120-140mAh / g; 2. The cycle life is short, about 300-500 times ; 3. The safety performance is poor. In actual use, the lithium cobalt oxide battery will explode; 4. The cobalt raw material used is a precious metal, which is expensive; 5. Cobalt is a heavy metal and is harmful to the environment. [0003] LiFePO 4 It is a new energy lithium-ion battery cathode material that has been promoted and used in recent years. It has the following advantages: [0004] 1. Fast charge and discharge performance: Lithium batteries made of lithium iron phosphate catho...

AI Technical Summary

Problems solved by technology

[0002] At present, commercial lithium-ion batteries basically use layered lithium cobalt oxide as the positive electrode material. The disadvantages are: 1. The actual capacity is low, at 120-140mAh / g; 2. The cycle life is short, about 300-500 times ; 3. The safety performance is poor. In the actual use process, lithium cobalt oxide batteries will explode; 4. The cobalt raw materials used are precious metals, which are expensive; 5. Cobalt is a heavy metal and is harmful to the environment.

[0009] 6. No memory effect

[0011] Preparation of LiFePO by existing solid-state sintering method 4 It can be applied to large-scale production, but the performance consistency of each batch of products is poor, and the actual operation of this method requires high-temperature sintering and long-term heat preservation, resulting in the inability to guarantee the consistency of final product performance, resulting in large energy consumption, and the entire production process High energy consumption and poor economy

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