A lithium titanate battery with high cycle performance

Abstract

The invention relates to the technical field of lithium ion batteries. In order to solve the problem of low cycle performance of the existing lithium titanate battery, the invention provides a lithium titanate battery with high cycle performance, which includes a positive electrode sheet, a negative electrode sheet, a diaphragm, and an electrolyte. and outer packaging, the active material on the positive electrode sheet is a ternary material, the active material on the negative electrode sheet is lithium titanate, the solvent of the electrolyte solution is organic carbonate, the electrolyte solution contains lithium salt, the electrolyte solution It also contains electrolyte additives and gas eliminators. The electrolyte additives contain ammonium percyanate and succinic acid. The diaphragm is a microporous film diaphragm or a non-woven diaphragm. Polyolefin or polyethylene terephthalate of stone particles and carboxymethyl cellulose fibers. The lithium titanate battery in the present invention is not easy to produce flatulence, has good cycle performance, and the diaphragm has good wettability and moisturizing performance for the electrolyte, and the present invention is suitable for use as a power battery.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a battery with high cycle performance using lithium titanate as a negative electrode material. Background technique [0002] At present, most commercial lithium-ion battery anode materials use various lithium-intercalated carbons and graphites. However, carbon-containing negative electrode materials have some disadvantages, such as the formation of a passivation film on the surface during the first cycle, which greatly consumes lithium ions in the positive electrode material, resulting in a large capacity loss; the potential of the carbon negative electrode is very close to that of lithium. Nearly, when the battery is overcharged, metal lithium may precipitate on the surface of the carbon electrode and cause safety problems; the speed of releasing energy is not fast enough, and it is not suitable for devices that require instantaneous high current. Lithium titanium...

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Problems solved by technology

But the disadvantage is that the above method can suppress the generation of gas by coating lithium titanate to a certain extent, but because it is difficult to achieve complete coating, it cannot fundamentally solve this problem, and the oxide Lithium ion conductivity is small, which affects the cycle performance and rate performance of the battery

However, the wetting performance of polyolefin itself to the electrolyte is insufficient, and the existence of the inorganic coating further makes the wetting of the composite separator insufficient to the electrolyte, resulting in an increase in the internal resistance of the battery and a decrease in the ion transmission rate, thereby affecting the cycle performance of the battery.

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