I. Differences between lithium-ion batteries and polymer lithium batteries
1. The raw materials are different. The raw material of lithium-ion batteries is electrolyte (liquid or colloid); the raw material of polymer lithium batteries is electrolyte, which can be polymer electrolyte (solid or colloid) or organic electrolyte.
2. In terms of safety, lithium-ion batteries are prone to explosion in high temperature and high pressure environments; polymer lithium batteries use aluminum-plastic film as the outer shell, and when organic electrolyte is used inside, they will not explode even when the liquid is very hot.
3. Different shaping: Polymer batteries can be made thin, with arbitrary area and shape because their electrolyte can be solid or gel-like rather than liquid. Lithium batteries, on the other hand, use electrolyte and require a sturdy outer shell as a secondary packaging to contain the electrolyte.
4. The cell voltages are different. Because polymer batteries use high-molecular materials, they can be made into multiple layers in the cell to achieve high voltage. However, the nominal capacity of a lithium battery cell is 3.6V. To achieve high voltage in practical applications, multiple cells need to be connected in series to form an ideal high-voltage operating platform.
5. Due to different manufacturing processes, polymer batteries are easier to produce when they are thinner, while lithium batteries are easier to produce when they are thicker. This allows lithium batteries to be used in a wider range of fields.
6. Capacity: The capacity of polymer batteries has not been effectively improved, and is even reduced compared to the standard capacity of lithium batteries.
II. How to view the energy storage value of lithium iron phosphate batteries
Lithium iron phosphate (LFP) battery energy storage systems can act as a buffer between various power sources and stable electricity demand, increasing the power generation capacity of unstable power sources such as wind and solar power. Wind power generation systems experience output power oscillations due to wind speed variations, while energy storage systems can provide stability and reactive power compensation to wind turbine output through rapid response and nearly equal charge-discharge cycles. Simultaneously, energy storage systems can regulate voltage and control system frequency in off-grid power generation systems.
Lithium iron phosphate battery energy storage systems can save on fixed equipment investment in power grid systems; improve the utilization rate of power grid equipment, reduce financial risks, avoid the occurrence of huge one-time investments with extremely low equipment utilization rates, and allow investments to be used in more needed and important situations; and reduce the operating costs for end users.
Pumped hydro storage accounts for over 90% of my country's energy storage methods, but the proportion of electrochemical energy storage has been steadily increasing in recent years. In 2020, the three major telecom operators' 5G investment increased exponentially compared to 2019. China Mobile's expected capital expenditure for 2020 was 179.8 billion yuan, of which approximately 100 billion yuan was planned for 5G-related investment, compared to 24 billion yuan in 2019—a five-fold increase. With the explosive growth in 5G base station construction, a significant increase in demand for lithium iron phosphate batteries is expected.
III. Factors Affecting the Performance of Mobile Phone Lithium Batteries
Lithium-ion batteries are a type of battery that uses lithium metal or lithium alloys as the positive/negative electrode materials and a non-aqueous electrolyte solution. The earliest lithium metal battery was proposed and studied by Gilbert N. Lewis in 1912. In the 1970s, MS Whittingham proposed and began researching lithium-ion batteries. Due to the highly reactive chemical properties of lithium metal, its processing, storage, and use require very strict environmental controls. With the development of science and technology, lithium-ion batteries have become mainstream. Mobile phone lithium batteries are one of the lithium-ion batteries we commonly use.
Battery short circuit: A short circuit can have varying degrees of consequences for a mobile phone lithium battery, such as increased electrolyte level, increased internal pressure, and battery leakage. Connecting the battery's external terminals to any conductor will cause an external short circuit, damaging battery performance. If the safety valve fails, it may even cause the battery to explode. Therefore, never allow the battery to be externally short-circuited.
Excessive temperature: Temperature is one of the environmental factors affecting battery performance, with the greatest impact on the charging and discharging performance of mobile phone batteries. The electrochemical reactions and transport speeds of mobile phone lithium batteries are related to ambient temperature. When the temperature rises or falls, the reaction rate and transport speed of the electrodes also increase or decrease, thus affecting the battery's charging and discharging performance. Therefore, the temperature of mobile phone lithium batteries should not be too high during use.
