A wound-rolled battery

Abstract

The invention discloses a wound-wrapped battery, which includes an electric core. The electric core is formed by winding a plurality of winding structural units with a continuous diaphragm as a carrier. The winding structural unit includes horizontally arranged diaphragms separated by diaphragms. The set positive electrode piece and negative electrode piece are wound as a whole to form a winding structure unit, the number of winding turns is 0.5*N turns, and the formed winding structure unit is negative electrode / diaphragm / positive electrode / diaphragm / negative electrode / diaphragm / positive electrode / Separator / negative electrode / separator / positive electrode / separator / negative electrode alternately present any part of the repeating unit that can be intercepted, and multiple wound structural units are rolled to form a battery electrode group. The invention not only has no arc area, low loss, uniform cyclic expansion, high production efficiency, and even distribution of electrolyte, but also the winding and stacking method of the continuous diaphragm makes the winding core more stable, which is convenient for the transfer of the winding core in the automatic production line. On the one hand, this layer of continuous diaphragm also balances the uniformity of electrolyte distribution in the multilayer pole piece.

Description

Technical field [0001] The invention relates to the field of batteries, in particular to a wound-to-roll type battery. Background technique [0002] Nowadays, the use of lithium-ion batteries in power tools has exploded. The cost, production efficiency, long-term life and consistency of power batteries are in urgent need of rapid breakthroughs. Therefore, the research on the structure of battery components is the top priority. The current battery assembly structure has winding, laminated, bag-making, stack-folding and other structures: the winding structure is to separate the continuous positive sheet and the negative sheet through a separation membrane for winding; In the type structure, specific structural units are continuously stacked and separated by a separation membrane; the bag-making structure is to first bag the negative electrode into a separator bag, and then carry out a layer-by-layer structure; stack-fold The structure is first to make stacked structural units, and...

AI Technical Summary

Problems solved by technology

[0003] However, the batteries of these several structures have their own defects, which are as follows: (1) The winding structure is manufactured by densely winding the long-sheet negative electrode and the long-sheet positive electrode. As a result, the battery structure is Circular or elliptical, the stress due to the expansion and contraction of the electrodes during the charging and discharging of the battery accumulates in the battery structure, and when the stress accumulation exceeds a certain limit, the battery structure deforms, and the deformation of the battery structure causes a gap between the electrodes If there is an uneven gap between them, the cycle performance of the battery will deteriorate sharply, and the safety of the battery cannot be guaranteed due to the short circuit inside the battery; (2) The laminated structure stacks multiple unit negative electrodes and multiple unit positive electrodes in sequence To manufacture a stacked battery structure, it takes a lot of time and effort to perform sequential stacking processing, resulting in low production efficiency in this process; (3) bag-making structure, which increases the low-efficiency bag-making process compared to the stacked type (4) The stacked-folded structure has high production efficiency and stable structure, but the difference between electrolyte layers will affect the long-term characteristics of the battery

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