With the continuous development of new energy vehicles, more and more attention has been paid to power batteries. Battery, motor and electronic control system are the three key components of new energy vehicles, of which power battery is the most critical part, which can be said to be the “heart” of new energy vehicles, so what are the power batteries of new energy vehicles? What about major categories?
1. Lead-acid battery
A lead-acid battery (VRLA) is a battery whose electrodes are mainly made of lead and its oxides, and the electrolyte is a sulfuric acid solution. In the charged state of the lead-acid battery, the main component of the positive electrode is lead dioxide, and the main component of the negative electrode is lead; in the discharged state, the main component of the positive and negative electrodes is lead sulfate. The nominal voltage of a single-cell lead-acid battery is 2.0V, which can be discharged to 1.5V and charged to 2.4V; in applications, 6 single-cell lead-acid batteries are often connected in series to form a nominal 12V lead-acid battery , and 24V, 36V, 48V, etc.
As a relatively mature technology, lead-acid batteries are still the only battery for electric vehicles that can be mass-produced because of their low cost and high-rate discharge capability. However, the specific energy, specific power and energy density of lead-acid batteries are very low, and electric vehicles using this as a power source cannot have a good speed and cruising range .
2. Nickel-cadmium batteries and nickel-metal hydride batteries
Nickel-cadmium battery (Nickel-cadmium battery, often referred to as NiCd, pronounced “nye-cad”) is a popular battery. This battery uses nickel hydroxide (NiOH) and metal cadmium (Cd) as chemicals to generate electricity. Although its performance is better than that of lead-acid batteries, it contains heavy metals, which will pollute the environment after being used and abandoned.
The nickel-cadmium battery can be charged and discharged more than 500 times, which is economical and durable. Its internal resistance is small, the internal resistance is small, it can be quickly charged, and it can provide a large current for the load, and the voltage change is small during discharge, which is a very ideal DC power supply battery. Compared with other types of batteries, nickel-cadmium batteries can withstand overcharge or overdischarge.
Ni-MH battery is composed of hydrogen ion and metal nickel, and its power reserve is 30% more than that of Ni-Cd battery. .
3. Lithium battery
Lithium battery is a kind of battery that uses lithium metal or lithium alloy as negative electrode material and uses non-aqueous electrolyte solution. Lithium batteries can be roughly divided into two categories: lithium metal batteries and lithium ion batteries. Lithium-ion batteries do not contain lithium in the metallic state and are rechargeable.
Lithium metal batteries generally use manganese dioxide as the positive electrode material, metal lithium or its alloy metal as the negative electrode material, and use a non-aqueous electrolyte solution. Lithium battery materials are mainly composed of: positive electrode material, negative electrode material, separator, electrolyte.
Among the cathode materials, the most commonly used materials are lithium cobalt oxide, lithium manganate, lithium iron phosphate and ternary materials (polymers of nickel, cobalt and manganese). The positive electrode material occupies a large proportion (the mass ratio of positive and negative electrode materials is 3: 1~4: 1), because the performance of the positive electrode material directly affects the performance of the lithium-ion battery, and its cost also directly determines the cost of the battery.
Among the anode materials, the current anode materials are mainly natural graphite and artificial graphite. The anode materials being explored include nitrides, PAS, tin-based oxides, tin alloys, nano anode materials, and some other intermetallic compounds. As one of the four major components of lithium battery, the negative electrode material plays an important role in improving the capacity and cycle performance of the battery, and is the core link in the midstream of the lithium battery industry.
A fuel cell is a non-combustion electrochemical energy conversion device. The chemical energy of hydrogen (and other fuels) and oxygen is continuously converted into electrical energy. Its working principle is that H2 is oxidized into H+ and e- under the action of the anode catalyst, H+ reaches the positive electrode through the proton exchange membrane, reacts with O2 at the cathode to generate water, and e- reaches the cathode through the external circuit, and the continuous reaction generates current. Although the fuel cell has the word “battery”, it is not an energy storage device in the traditional sense , but a power generation device. This is the biggest difference between a fuel cell and a traditional battery.
Post time: Jun-05-2022