Non-aqueous electrolyte battery

Abstract

In a non-aqueous electrolyte battery having a positive electrode ( 1 ), a negative electrode ( 2 ), a separator ( 3 ), and a non-aqueous electrolyte, an electrolyte diffusion restricting layer ( 11 ) for restricting diffusion of the electrolyte is formed between the positive electrode ( 1 ) and the separator ( 3 ) to accelerate deterioration of the positive electrode, and an electrolyte diffusion promoting layer ( 21 ) for promoting diffusion of the electrolyte is formed between the negative electrode ( 2 ) and the separator ( 3 ) to hinder deterioration of the negative electrode.

Description

technical field [0001] The present invention relates to a nonaqueous electrolyte battery including a lithium ion battery, and particularly relates to a battery structure that is excellent in safety after long-term cycle use and can exhibit high reliability even in a battery structure having a high capacity. Background technique [0002] In recent years, the size and weight of mobile information terminals such as mobile phones, notebook PCs, and PDAs has rapidly increased, and further increases in capacity have been demanded for batteries as their driving power sources. Lithium-ion batteries, which have high energy density among secondary batteries, have been increasing in capacity year by year. Especially, with the enhancement of functions such as color function, animation function, communication function and music function of mobile phones, the power consumption is further increasing. There is a strong demand for higher capacity or higher performance for long-time reproduct...

AI Technical Summary

Problems solved by technology

[0006] In the conventional battery structure, the film thickness of the separator is large, and the volume change accompanying the expansion and contraction of the electrode and the necessary buffering effect of the electrolyte are compensated by the separator. However, as the capacity increases, the film thickness of the separator becomes thinner. In addition, due to the increase in the coating amount of the electrode, the necessary electrolyte solution per unit area has to be increased. In addition, the electrolyte solution that should be supplemented in the past is squeezed out of the wound body system, and it needs to be further inward from here. diffusion

As this cycle is repeated, the supply of the electrolyte cannot keep up. Especially in the negative electrode with a large volume change, the electrolyte will be insufficient and the reaction will become inhomogeneous.

As a result, there is little performance degradation in the positive electrode that does not require much electrolyte, but the degradation is accelerated in the negative electrode that requires a large amount of electrolyte. Therefore, the balance of lithium storage and detachment capabilities of the positive and negative electrodes is disrupted, and the quality is easily accelerated. Conditions of deterioration (specifically, there are adverse conditions in which dryness occurs during the charge-discharge cycle, lithium is deposited on the negative electrode, and as a result, a short circuit occurs between the positive and negative electrodes)

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