Just like when buying a car, you consider the engine. One of the most important things to consider when purchasing a power source is the battery, which is the energy storage part of the battery. The quality of the cell directly determines the quality of the RV battery, and the quality of the battery determines the quality of the power supply. It is also a guarantee of safety. The battery cell can realize over-current protection, over-charge protection, over-discharge protection, short-circuit protection, over-current protection, over-temperature protection, etc. A good battery has a long life, stable performance, and safety. Battery life, electric vehicle charging and discharging, and all applications of external power sources are also inseparable from the functions of batteries.
The most commonly used in the market are lithium iron phosphate batteries, polymer lithium batteries, and ternary lithium batteries. These three batteries have their characteristics. What is the difference between these three batteries?
- LiFePo4 battery
Lithium iron phosphate is a lithium-ion battery using lithium iron phosphate as the positive electrode material. Lithium battery cathode materials mainly include lithium cobalt oxide, manganate, nickelate, ternary materials, and iron phosphate. Among these, lithium cobalt oxide is currently the cathode material used in most lithium-ion batteries. For the cathode material of LiFePO4, the raw material source is relatively wide, the service life is long, the safety index is also high, and the pollution is low. It shows a very strong overall performance in many cathode materials.
When the 12v lithium ion battery is charged, the lithium-ion Li in the positive electrode migrates to the negative electrode through the polymer membrane; During the discharge process, the lithium-ion Li in the negative electrode migrates through the membrane to the positive electrode. Lithium-ion batteries are named for lithium ions, which move back and forth as they charge and discharge.
Advantages of lithium iron phosphate battery:
- The lithium iron phosphate battery has a long service life, with a service life of more than 2000 times. Under the same conditions, lithium iron phosphate batteries can be used for 7 to 8 years.
- Safe to use. The lithium iron phosphate battery has undergone rigorous safety testing and will not explode even in a traffic accident.
- Fast charge. With a special charger, the battery can be fully charged in 40 minutes at 1.5C.
- The lithium iron phosphate battery is resistant to high temperatures, and the hot air value of the lithium iron phosphate battery can reach 350-500 degrees Celsius.
- The lithium iron phosphate battery has a large capacity.
- The lithium iron phosphate battery has no memory effect.
- Lithium iron phosphate batteries are environmentally friendly, non-toxic, environmentally friendly, with a wide range of raw materials and relatively cheap prices.
- Polymer lithium battery
Polymer lithium batteries generally refer to polymer lithium-ion batteries. The positive and negative materials used in polymer lithium batteries are the same as liquid lithium ions. The positive electrode materials are divided into lithium cobalt oxide, manganate, ternary materials, and lithium iron phosphate. The negative electrode is made of graphite, and the battery’s operation principle is the same. The principle of the polymer lithium battery is the same as that of liquid lithium. The main difference is that the electrolyte is different from liquid lithium. The main structure of the battery includes three elements: a positive electrode, a negative electrode, and an electrolyte. The so-called polymer lithium-ion battery means that at least one or more of these three main structures use polymer materials as the main battery system. In the currently developed polymer lithium-ion battery system, polymer materials are mainly used in positive electrodes and electrolytes.
Advantages of polymer lithium battery：
- The working voltage of a single battery is 3.6V-3.8V, much higher than the 1.2V voltage of nickel-hydrogen and nickel-cadmium batteries.
- Large capacity density, its capacity density is 1.5~2.5 times that of a Ni-MH battery or Ni-Cd battery or higher.
- Self-discharge is small, and its loss of capacity is small even after long-term abandonment.
- Long service life, the service life can be more than 500 times in normal use.
- There is no memory effect, no need to dump the remaining power before charging, and it is easy to use.
- The safety performance is good. The polymer lithium battery uses soft aluminum-plastic packaging in the structure, which is different from the liquid battery’s metal shell. Once a safety hazard occurs, the liquid battery can easily explode, and the polymer battery can only explode.
- Small thickness, can be made thinner. The ultra-thin battery can be assembled into a credit card. Ordinary liquid lithium batteries first adjust the shell and then plug the positive and negative materials. The thickness is under 3.6mm, and there is a technical bottleneck. Polymer batteries do not have this problem. The thickness can be less than 1mm, which meets the current demand for mobile phones.
- The polymer electrolyte battery is lightweight and does not require a metal shell for protective outer packaging. The weight of a polymer battery is 40% lighter than a steel shell lithium battery of the same capacity and 20% lighter than an aluminum shell battery.
- Large-capacity polymer batteries have 10-15% higher capacity than same-sized steel shell batteries and 5-10% higher capacity than aluminum shell batteries. It is the first choice for color-screen mobile phones and MMS mobile phones. MMS cell phones also mostly use polymer batteries.
- Small internal resistance. The internal resistance of polymer batteries is lower than that of normal liquid batteries. At present, the internal resistance of household polymer batteries can be even lower than 35mΩ, which greatly reduces the battery’s consumption and extends the mobile phone’s standby time. Level according to international standards. This polymer lithium battery, which supports large discharge currents, is an ideal choice for remote control models and the most promising product to replace Ni-MH batteries.
- The shape can be customized. The manufacturer is not limited to the standard shape but can be made into a suitable size economically. The polymer lithium battery can increase or decrease the thickness of the battery cell according to customer needs and develop new battery cell models. The price is low, and the mold opening cycle is short. Some can even be cut to the phone’s shape to fully use the battery case space and improve battery capacity.
- Simple protection board design. Due to polymer materials, the battery core will not ignite or explode, and the battery has sufficient safety. Therefore, it can be assumed that the design of the polymer battery protection circuit omits the PTC and fuse, thereby saving battery costs.
- Ternary lithium battery
Ternary lithium battery refers to a lithium battery using lithium nickel cobalt manganate as the positive electrode material and graphite as the negative electrode material. Unlike lithium iron phosphate, the ternary lithium battery has a high voltage platform, which means that the ternary lithium battery has a greater specific energy and specific power with the same volume or weight. In addition, ternary lithium batteries have great advantages in terms of high-speed charging and low-temperature resistance. Ternary lithium batteries are more suitable for current and future domestic electric vehicles than lithium iron phosphate batteries.
Ternary lithium batteries have better low-temperature resistance and are the main technical way to produce low-temperature lithium batteries. At minus 20°C, ternary lithium batteries can release 70.14% capacity, while lithium iron phosphate batteries can only release 54.94% capacity. And because under low-temperature conditions, the discharge platform of the ternary lithium battery is much higher than the voltage platform of the lithium iron phosphate battery and starts faster.
Lithium iron phosphate battery is better than ternary lithium battery. The academic life of the ternary lithium battery is 2000 times, but the capacity drops to 60% after 1000 cycles. Even the best brand in the business, Tesla, after 3000 times the power. It can only maintain 70% power, while the lithium iron phosphate battery has 80% capacity after the same cycle.