Preparation method of slurry for lithium titanate battery

Abstract

The invention discloses a preparation method of slurry for a lithium titanate battery. The method comprises the steps of (1) preparing glue, namely adding a binder and a certain amount of solvent to a stirring tank A and stirring evenly for the first time; (2) carrying out dry mixing of powder, namely adding a conductive agent and an active substance to a stirring tank B according to the designed weight proportion, carrying out full dry mixing and stirring for a certain period of time and adding a certain amount of anhydrous oxalic acid when the active substance is lithium titanate; and (3) adding the glue which is stirred for the first time in the stirring tank A to the stirring tank B and then fully stirring evenly until the viscosity of the slurry is 6,000-10,000mpa.s. Compared with the prior art, the preparation method has the beneficial effects that (1) the steps (1) and (2) of the method can be simultaneously carried out and the preparation time of the slurry can be obviously shortened; and (2) a certain amount of anhydrous oxalic acid is added to the lithium titanate slurry, so that the pH of the slurry can be improved and the long-term cycle performance of the lithium titanate battery can also be improved.

Description

[0001] 【Technical field】 [0002] The invention relates to the technical field of lithium batteries, in particular to a preparation method of lithium titanate battery slurry. [0003] 【Background technique】 [0004] At present, with the advancement of science and technology and the continuous improvement of human demand for new energy, thanks to the rapid popularization of new energy vehicles, the demand for lithium-ion batteries is also increasing, and the requirements for battery performance are also constantly improving, but The most fundamental premise is to solve its safety problems. In addition, further improving the low-temperature and fast charging capabilities of lithium-ion batteries is also a major field in the current market. [0005] Commercial lithium-ion batteries with graphite negative electrodes have some disadvantages. For example, lithium dendrites are easy to form when overcharged, causing a short circuit of the battery and affecting the safety performance o...

AI Technical Summary

Problems solved by technology

[0005] Commercial lithium-ion batteries with graphite negative electrodes have some disadvantages. For example, lithium dendrites are easy to form when overcharged, causing a short circuit of the battery and affecting the safety performance of the battery; And other phenomena, and the SEI film is formed when the negative electrode is charged and discharged for the first time, resulting in low initial charge and discharge efficiency and large irreversible capacity; in addition, the carbon material platform is low, which is easy to cause electrolyte decomposition, etc., which will cause safety hazards and service life. Fast charging, etc.

[0006] Lithium titanate is a zero-strain material with a potential of about 1.55V to lithium. It is not easy to generate lithium dendrites, has better safety performance, and has strong fast charging and low-temperature charging capabilities, making it have good cycle performance, safety performance, fast charging and Low-temperature charging capability has a large market space, and it is bound to be the first choice for fast-charging power batteries in the future. However, lithium titanate is a nano-scale material, ultra-fine powder, and has a large specific surface area. According to the traditional method of preparing slurry It is difficult to prepare a uniform slurry, resulting in poor coating effect of the pole piece, many particles, and decreased consistency and stability of the battery, resulting in poor rate performance and poor cycle performance of lithium titanate batteries

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