Key technology development of lithium battery -Lithium - Ion Battery Equipment
The lithium battery uses carbon materials as the negative electrode and lithium containing compounds as the positive electrode. There is no metal lithium, only lithium ion. It is a secondary battery (rechargeable battery). It mainly depends on lithium ion moving between the positive and negative electrodes to work. In the process of charging and discharging, Li+is embedded and de-embedded between the two electrodes: during charging, Li+is de-embedded from the positive electrode and embedded into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; The opposite is true when discharging. When charging the battery, lithium ion is generated on the positive pole of the battery, and the generated lithium ion moves to the negative pole through the electrolyte. The carbon as the anode has a layered structure, which has many micropores. The lithium ions that reach the anode are embedded into the micropores of the carbon layer. The more lithium ions embedded, the higher the charging capacity. Similarly, when the battery is discharged (that is, when we use the battery), the lithium ion embedded in the carbon layer of the negative electrode comes out and moves back to the positive electrode. The more lithium ions returned to the positive electrode, the higher the discharge capacity.
Lithium battery has obvious advantages. The working voltage of high voltage single battery is up to 3.7-3.8V; Large energy, the actual specific energy that can be achieved is about 555Wh/kg; The cycle life is long, which can reach more than 500 times, or even more than 1000 times; Good safety performance; The self-discharge rate of fully charged Li-ion is about 2% after one month storage at room temperature; Fast charging. But unlike other rechargeable batteries, the capacity of lithium batteries will slowly decline.
Core tips: lithium batteries for new energy storage devices
Driven by the rapid rise of the global electric vehicle market, the global lithium battery has risen rapidly. In 2018, the global lithium battery industry reached US $41.2 billion, with a capacity of 200GWh. In 2018, China's lithium battery market was 170 billion yuan, power lithium battery 89 billion yuan, consumer battery 75 billion yuan, and energy storage battery accounted for 3-4%. Since 2017, power lithium batteries have exceeded consumer batteries.
For the power lithium battery industry, 2.1 million new energy vehicles were sold globally in 2018, of which 69% were pure electric and 31% were plug-in hybrid. According to the issuance of the "Medium and Long-term Development Plan for the Automobile Industry" jointly issued by the Ministry of Industry and Information Technology, the Development and Reform Commission and the Ministry of Science and Technology in 2017, the annual production and sales of new energy vehicles will reach 2 million by 2020, and by 2025, new energy vehicles will account for more than 20% of the total production and sales of automobiles.
Core tips: lithium sulfur battery for new energy storage device
Lithium-sulfur battery is a kind of lithium battery, which uses sulfur element as the positive electrode and metal lithium as the negative electrode. The lithium-sulfur battery uses sulfur as the positive reaction material and lithium as the negative electrode. During discharge, the negative reaction is that lithium loses electrons and turns into lithium ions, and the positive reaction is that sulfur and lithium ions and electrons react to generate sulfide. The potential difference between the positive and negative reactions is the discharge voltage supplied by the lithium-sulfur battery. Under the application of applied voltage, the positive and negative reactions of lithium-sulfur batteries are reversed, which is the charging process. Simple sulfur is abundant in the earth, with low price and environmental friendly characteristics. In addition to very high energy density, lithium-sulfur battery has low production cost, low toxicity after use, basically no pollution to the environment, and low energy consumption for recycling. It is a very promising lithium battery. However, the biggest disadvantage is that its recycling times are relatively low, which greatly increases the use cost of lithium-sulfur batteries.(Lithium - Ion Battery Equipment)
The research and development of lithium-sulfur battery in foreign countries is early, and it is in the early stage of industrialization. The lithium-sulfur battery developed and produced by American SionPower Company in 2016, 20Ah, 400Wh/kg, 1C cycle 350 times; The lithium sulfur battery developed and manufactured by OXIS in the UK in 2018 has an energy density of 425-500Wh/kg and a cycle of less than 100 times.