Two-time home energy storage ternary lithium battery, lithium battery foundry

There is a wide range of energy storage batteries. Among them, there is great potential to be tapped in our new energy storage field. At present, the rapid development of wind and solar power and the tight grid dispatching, urgently need more energy storage power stations for peak and frequency regulation. At the same time, industrial and commercial energy storage and household energy storage have great potential, and supporting photovoltaic power stations can achieve clean energy and achieve self-sufficiency. Energy storage batteries and devices are indispensable components of solar photovoltaic power generation systems to store electrical energy. Its main function is to store electrical energy in the photovoltaic power generation system and supply power to the load when the amount of sunlight is insufficient, at night and in emergency situations. Commonly used energy storage batteries include lead-acid batteries, alkaline batteries, lithium batteries, and super capacitors. They are used in different occasions or products. Currently, lithium batteries are developing rapidly.

In 2016, in the international energy storage application market, new energy sources such as wind power were connected to the grid accounted for about 43%, frequency modulation and auxiliary services accounted for about 24%, and power transmission and distribution accounted for 19%. %, distributed power generation and micro-grid account for about 13%. In my country's energy storage application market, distributed power generation and microgrid account for about 56%, new energy grid-connected applications account for about 35%, frequency modulation and ancillary services account for about 2%, and others account for about 7%. The application of new energy grid-connected, distributed power generation and micro-grid fields accounts for about my country's energy storage application market share.

As a bridge connecting the power generation side, the power supply side and the power consumption side, the significance of energy storage is very important. Simply put, the application of energy storage systems can effectively compensate for the randomness of renewable energy power generation, improve its consumption level and the stability of the grid; supporting distributed power, microgrids and even the energy Internet is to promote the main energy from fossil energy The key technology for the replacement of renewable energy.

Under the strong policy, the sales volume of electric vehicles from 2014 to 2015 has achieved a rapid growth of more than three times for two consecutive years, which has driven the rapid growth of lithium-ion power battery companies. development of. However, due to fierce competition and higher barriers to entry, many lithium battery companies have turned to the field of energy storage, which has a vast market but has not yet developed. In the exhibitions, summits, and conferences held in the past two years, lithium battery companies have launched energy storage products in an endless stream.

The advantages of large-scale production capacity will play a vital role in reducing the cost of energy storage batteries and power batteries. Judging from the current market competition pattern, lithium batteries and lead storage batteries occupy most of the electrochemical energy storage market. Lithium battery energy storage has gradually increased the proportion of new installed capacity in various energy storage systems in recent years, and the United States is in a position in the global installed capacity of lithium battery energy storage. It is expected that more and more lithium battery manufacturers will pay attention to this field in the future.

3. Battery pack management

Lithium battery management system (BatteryManagementSystem), BMS is composed of microcomputer technology, detection technology, etc. The function of the constituted device is not only to protect the battery from charging and discharging, but also to measure the remaining power of the battery, and to balance the charging of the single battery and other important functions.

(1) Guarantee the safety of the battery: in the process of battery charging and discharging, real-time collection of the terminal voltage and temperature of each battery in the electric vehicle battery pack, charging and discharging current and The total voltage of the battery pack prevents the battery from being overcharged or over-discharged.

(2) Accurately estimate the remaining battery capacity of the battery pack, and predict how much energy remains in the energy storage battery of the hybrid electric vehicle or the state of charge of the energy storage battery at any time. There is a certain relationship between battery power and voltage, but it is not a linear relationship. You cannot rely on voltage to convert the remaining power. It needs to be calculated by BMS.

(3) Balance among the single cells: that is, the single cells are balanced and charged, so that each battery in the battery pack reaches a balanced state.

Four. Selection and design of lithium battery

The lithium battery system includes battery cells and BMS battery management system. Provided by the manufacturer. The following points should be paid attention to when designing:

(1) The energy storage lithium battery pack needs to communicate with the inverter or the two-way energy storage converter PCS. A device with battery function and corresponding communication interface function.

(2) Compared with lead-acid batteries, energy storage lithium batteries have lower charge and discharge currents.

(3) If the system requires multiple battery packs, one battery pack needs to be equipped with a BMS system.