Lithium battery characteristics and technical analysis -Lithium - Ion Battery Equipment
Compared with traditional lead-acid batteries, nickel-chromium batteries, and nickel-metal hydride batteries, lithium-ion batteries do not contain toxic and harmful heavy metal elements such as lead, mercury, and cadmium, and the pollution is relatively light. Its electrolyte is organic solvent and lithium salt, most of which are non-toxic or low-toxic. Lithium-ion battery characteristics
(1) Voltage platform
Since different anode and cathode materials are used in lithium-ion batteries, the working voltage range of single cells is 3.7~4v, and the working voltage of lithium iron phosphate single cells with larger applications is 3.2v, 3 times that of NiMH 2 times as much as batteries and lead-acid batteries.
(2) Energy
The energy density of lithium-ion batteries for passenger cars is close to 200Wh/kg and is expected to reach 300Wh/kg by 2020.
(3) Long battery life
Due to the properties of electrochemical materials, the cycle time of Li-ion batteries is relatively long. Taking lithium iron phosphate as an example, the cycle times of a single battery can reach more than 2,000 times, while the cycle times of a group of batteries are only more than 1,000 times.
(4) Small impact on the environment
Lithium-ion batteries use light metal lithium. Although they do not contain harmful heavy metals such as mercury and lead, they are environmentally friendly and have little environmental pollution.
(5) Higher cost
The initial purchase cost of lithium-ion batteries is high. Take the lithium iron phosphate battery, the mainstream product of bus power lithium battery, as an example. The price is about 2500 yuan / degree. Due to the limitation of the number of cycles after a single battery is formed, the bus usually needs to replace the battery in about 3 years, which brings greater cost pressure to the operating unit.
(6) Small impact on power grid
First of all, due to the large-scale application of pure electric vehicles, due to the large charging demand, the harmonic interference of charging equipment on the power grid will be prominent, affecting the power supply quality of the power grid; secondly, in the case of fast charging, the charging power is relatively high (50kW passenger car, 150 -250kw passenger car, etc.), the charging ratio is large, which has a greater impact on the grid load.