Lithium battery of high specific energy and high power, and manufacturing method thereof

Abstract

The invention discloses a lithium battery of high specific energy and high power, and a manufacturing method thereof. A first cell 1 provides specific energy as high as 150Wh / kg; a second cell 2 provides high power needed in cell pulse; by virtue of the characteristics of uniform current density distribution, low cell heating amount and heat uniform diffusion of the second cell 2, the battery canprovide high power when a high energy state is maintained; and heat is provided for the second cell 2 by the heating amount of the first cell 1 at a low temperature, so that the second cell 2 also canprovide excellent pulse charging-discharging performance at a low temperature, thereby improving the normal temperature and low temperature pulse charging-discharging performance of the cells.

Description

technical field [0001] The invention relates to the field of battery manufacturing, in particular to a lithium battery with high specific energy and high power and a manufacturing method thereof. Background technique [0002] At present, the global energy and global warming crises caused by the excessive consumption of natural resources and environmental pollution are becoming more and more serious, and the popularity of automobiles is one of the main reasons for this phenomenon. In this environment, the electrification of automobiles has become In the future development trend, low-cost, light-weight, and non-polluting lithium batteries have become a new energy synonym that has attracted much attention. Based on this understanding, the demand for lithium batteries in domestic and foreign markets is increasing day by day. In the process of pure electrification of fuel vehicles, hybrid electric vehicles (HEV) are an important step that must be taken. The high-power battery sys...

AI Technical Summary

Problems solved by technology

High specific energy and high power batteries have become the focus of people's research. On the one hand, they can satisfy the output of high energy, and on the other hand, they can provide instantaneous high power. For the battery itself, there is a tendency to take care of both, and they cannot meet the requirements at the same time.

[0003] Facing the demand for high-power batteries in the market, it is very meaningful and important to develop a battery cell that can provide both high energy and high power, especially a battery suitable for low-temperature starting. According to the existing technology, the battery It is easy to provide large pulse charging power at room temperature, such as the power of the high-power lithium-ion battery for HEV trial-produced by Hitachi, Panasonic, SAFT, LG and GYC when the battery cell is pulsed for 10s under 50% DOD Density can reach above 1800W / kg. However, at low temperature (-20°C, -30°C), companies are only setting targets for high-power pulse charging. For example, USABC has made requirements for hybrid systems (at -30°C It can perform pulse charging with a power of 1.1kW for 5s and discharge for 1s), so the low-temperature charging technology of power-type batteries is in urgent need of breakthrough and improvement

The conventional idea for the development of power-type batteries is to use D50 smaller positive and negative electrode materials, reduce the surface density of the positive and negative electrodes, use a high-porosity (≥40%) diaphragm, and combine special additive electrolytes. However, The implementation of these measures will inevitably lead to a reduction in the energy density of the battery cell, and it is almost ineffective for low temperature pulse charge and discharge. The present invention solves these problems

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