The Rolls Royce Phantom series, as the flagship product of Rolls Royce cars, has undergone seven generations of evolution since the first Phantom was born in 1925. In 2017, the eighth generation Phantom was officially unveiled at the "Ultimate Masterpiece Exhibition of the Eighth Generation Phantom" in Mayfair, London. Every Phantom embodies the hard work and wisdom of Rolls Royce engineers and designers, using cutting-edge technology and high-quality materials to ensure both vehicle performance and comfort.  Until today, there are still a large number of Rolls Royce enthusiasts who are crazy about it. In order to meet the needs of the times, many people choose to use it better through modification, and lithium batteries play a very important role here.  We are pleased to see that BOSA’s 105Ah lithium battery module is used in the modification process of this Rolls Royce vintage car. The addition of lithium batteries can provide it with stronger power, allowing this vintage car to run on the road again.  Bosa EnergyBosa Energy with 150GWH capacity and over 400,000 electric bus/utility vehicle application experience we are listing first 5 in China power battery industry, actually in  2023 we are the number 3 on li-ion cell delivery in China Market. We cooperate with Yutong/Geely/Damiler etc. We are also offering Container ESS systems and delivered 5GWh ESS in 2023. In local market, we are offering OEM service for Changan, CALB, National grid, Ping Gao Electric , Xuji electronics, Ruineng electronics, they are our main Container ESS suppliers in China Market. Our daily output capacity at present is 10Mwh and production capacity 20GWh; We are the most professional supplier of marine lithium batteries in China, and our export volume of marine batteries consistently ranks among the top three in China; We are also the top 1 exporter of lithium battery modules in China, specializing in providing various lithium battery module solutions. For excellent quality and performance our products are popular in more than 30 countries in the world. We also have established warehouse in Germany and Netherlands to provide safety stock timely delivery for our customers. l Customized and Flexiblel High Delivery capacityl Wide Applicationsl Rich experience on Lithium battery pack 

1. Types of energy density① Mass energy density: refers to the energy stored per unit mass of the battery, the unit is Wh/kg② Volume energy density: refers to the energy stored per unit volume of the battery, the unit is Wh/L2. Factors affecting energy density① Battery materials: The properties of materials such as positive electrode, negative electrode and electrolyte directly affect the battery energy density.② Battery structure: The electrode structure, electrolyte structure, and battery packaging and integration technology will affect the energy density.③ Battery preparation process: The electrode preparation process, electrolyte preparation process, and battery assembly and packaging process also have an impact on the energy density.3. Methods to improve energy density① Improvement of electrolyte and diaphragm: optimize electrolyte performance and improve ion transmission efficiency.② Battery structure design: adopt flattened, thin-sheet design, or multi-electrode structure design, etc. ③ Manufacturing process optimization: reduce active material loss and improve battery capacity and energy efficiency by improving manufacturing process.4.Energy density type selectionWhich energy density to choose depends on the needs of the specific application scenario. If long battery life and light weight are required, then a battery with higher mass energy density will be a better choice. On the contrary, if you need to obtain maximum energy storage in a limited space, a battery with higher volume energy density will be more suitable.

1. The concept of lithium battery edge resistanceThe edge resistance of lithium batteries refers to the resistance of the internal materials and electrolytes of the battery to the discharge and charge of the battery. It reflects the electron conduction capacity inside the battery and directly affects important performance indicators such as the battery's power output, energy efficiency and charging time.2. Common phenomena of poor edge resistance and their causes① High resistance: Too high edge resistance is one of the common problems of lithium batteries. This may be caused by low electrolyte conductivity, poor material conductivity, large contact resistance or unreasonable internal structure of the battery.② Unstable resistance: The instability of edge resistance may be caused by factors such as expansion and contraction of electrode materials, decomposition of electrolyte or passivation of electrode surface.③ Excessive local resistance: In lithium batteries, local resistance may be too high, which is usually caused by defects or short circuits in certain areas inside the battery.④ Increased contact resistance: The increase in contact resistance may be caused by poor contact between electrode and electrolyte, contamination or corrosion of electrode surface.4. Solutions to poor edge resistance① Optimize electrolyte formula: Select electrolyte with high conductivity and optimize its composition and concentration to improve the conductivity of electrolyte.② Improve material conductivity: Use positive and negative electrode materials with better conductivity, or improve the conductivity of materials through surface treatment and other methods. ③ Reduce contact resistance: Ensure good contact between the electrode and the electrolyte. The contact resistance can be reduced by optimizing the electrode structure design, improving the electrode surface treatment, etc. ④ Optimize the internal structure of the battery: Rationally design the structure of the battery, reduce the distance between the electrodes, and optimize the diffusion path of the electrolyte to reduce the internal resistance of the battery. ⑤ Quality control and testing: During the production process, strengthen quality control, conduct strict resistance tests on the battery, and promptly discover and eliminate products with poor edge resistance.

Definition of power batteries and energy storage batteriesEnergy storage batteries are battery systems used to store electrical energy. They are able to convert electrical energy into chemical energy, store the charge in the battery, and then release it when needed. Energy storage batteries are usually designed for long-term energy storage and charging and discharging, and play an important role in grid dispatching, peak load reduction, and power management. The key features of energy storage batteries are high capacity, long cycle life, and stable performance.Power batteries are specifically used to provide the power required by electric vehicles. They need to have high energy density and high power output to meet the requirements of electric vehicles for acceleration performance and mileage. The design of power batteries focuses on improving the battery's charging speed, discharge speed, and cycle life. At the same time, safety is also an important aspect of power batteries to ensure reliable operation under various conditions.Differences in application scenariosEnergy storage batteries are widely used in power grid energy storage, household energy storage, industrial and commercial energy storage, communication base stations and other fields. The design requirements of energy storage batteries are mainly optimized for energy density and long-term storage to meet the needs of large capacity and long-lasting energy storage.Power batteries are used in new energy passenger vehicles, commercial vehicles, special vehicles, engineering machinery and equipment, ships, etc. Power batteries pay more attention to power density and short-term high power output to meet the needs of electric vehicles for fast acceleration and long mileage. Compared with energy storage batteries, power batteries have higher requirements for energy density and power density. Furthermore, because power batteries are limited by the size and weight of the car and the acceleration at startup, power batteries have higher performance requirements than ordinary energy storage batteries.Differences in system compositionThe power battery PACK is basically composed of the following five systems: battery module, BMS, thermal management system, electrical system and structural system.The energy storage battery system is mainly composed of battery packs, BMS, EMS, PCS and other electrical equipment.Differences in battery managementAs the core component of the battery system, BMS determines whether the various components and functions of the battery pack can be coordinated and consistent, and is directly related to whether the battery pack can safely and reliably provide power output for electric vehicles.The energy storage battery management system is similar to the power battery management system, but the power battery system is in high-speed electric vehicles, and has higher requirements for the power response speed and power characteristics of the battery, the SOC estimation accuracy, and the number of state parameter calculations. The relevant adjustment functions also need to be implemented through BMS.Can energy storage batteries and power batteries be mixed?Energy storage batteries cannot be used in electric vehicles. There are different rates, internal resistances, capacities, and voltages between the two. Energy storage batteries generally have lower power density.Power lithium batteries can be used as energy storage batteries, but both power batteries and power control systems have high cost factors, which will lead to less than ideal economic benefits.It is understood that energy storage lithium batteries also have power types, such as those that support a stable current discharge capacity of about 5C and are widely used in frequency modulation. Some companies will reuse retired power batteries as energy storage batteries for household storage and mobile energy storage.

Why do lithium battery packs bulge?There are three main reasons for lithium battery bulging:①Manufacturer production process problemsThe battery coating is uneven, and dust particles are mixed into the electrolyte. These may cause the lithium battery pack to bulge when the user uses it.②User daily use habitsIf the user uses lithium battery products improperly, such as overcharging and overdischarging, or continuous use in extremely harsh environments, it may also cause lithium batteries to bulge. Among them, the reasons for bulging caused by overcharging and overdischarging are as follows:Bulging caused by overcharging: Overcharging will cause all the lithium atoms in the positive electrode material to run into the negative electrode material, causing the originally full grid of the positive electrode to deform and collapse, which is also a major reason for the decrease in lithium battery power. In this process, the number of lithium ions in the negative electrode increases, and excessive accumulation causes lithium atoms to grow crystals, causing the lithium battery to bulge.Bulging caused by overdischarge: During the first charge and discharge process of liquid lithium-ion batteries, the electrode material and the electrolyte react at the solid-liquid interface to form a passivation layer covering the surface of the electrode material. The formed passivation layer can effectively prevent the passage of electrolyte molecules, but Li+ can be freely embedded and removed through the passivation layer, which has the characteristics of a solid electrolyte. Therefore, this passivation film is called "solid electrolyte interface", or SEI for short. The SEI film protects the negative electrode material, making the material structure less likely to collapse, and can increase the cycle life of the electrode material. The SEI film is not static, and there will be a little change during the charge and discharge process, mainly because some organic matter will undergo reversible changes. After the battery is over-discharged, the SEI film is reversibly destroyed, and the SEI that protects the negative electrode material is destroyed, causing the negative electrode material to collapse, thus forming a bulging phenomenon.These two factors will cause a violent reaction similar to a short circuit to occur inside the battery during use, generating a large amount of heat, which will cause the electrolyte to decompose and gasify, and the battery will bulge.③ Long-term non-use and improper storageThe battery has not been used for a long time and has not been well preserved. When it is exposed to air for a long time and is not used, and the battery is fully charged. Since air is conductive to a certain extent, if the battery is left for too long, it is equivalent to the positive and negative poles of the battery being in direct contact, causing a chronic short circuit. Once a short circuit occurs, heat will be generated, and some electrolytes will decompose or even vaporize, leading to bulging.The capacity of bulging lithium batteries is seriously damaged and there are safety hazards. It is recommended not to use them.Waste lithium batteries should be processed through professional recycling channels to prevent environmental pollution.

1. The impact of low battery temperature on battery discharge capacityCapacity is one of the most important parameters of lithium batteries, and its size changes with temperature. The two curves in the figure below are temperature capacity curves obtained by discharging the battery at 0.1C and 0.3C at different temperatures.Obviously, as the temperature rises, the capacity gradually increases. The capacity at -20℃ is only about 60% of the capacity at 15℃. In addition to capacity, the open circuit voltage of the battery will also decrease with increasing temperature. We all know that the energy contained in the battery is the product of capacity and terminal voltage. When both multiples decrease, the energy in the battery must be the superposition of the two decreasing effects.When the battery temperature is low, the activity of the positive electrode material decreases, which reduces the number of lithium ions that can move and bring discharge current, which is the fundamental reason for the decrease in capacity.2. The influence of low battery temperature on battery internal resistanceThe relationship between lithium battery temperature and resistance is shown in the figure below. Different curves represent different charging levels of the battery itself. In any charging situation, the internal resistance of the battery will increase significantly as the temperature decreases. The lower the charge, the greater the internal resistance, and this trend remains unchanged with temperature changes.When the battery temperature is low, the diffusion and mobility of charged ions in the positive and negative electrode materials become worse, and it is difficult to pass through the passivation film between the electrode and the electrolyte. The transfer speed in the electrolyte is also reduced, and a large amount of heat is generated during the transfer process.After the lithium ions reach the negative electrode, the diffusion inside the negative electrode material also becomes unsmooth. Throughout the process, the movement of charged ions becomes very difficult. From the outside, it means that the internal resistance of the battery cell has increased.3. The impact of low battery temperature on battery charging and discharging efficiencyThe following curve is the curve of charging efficiency changing with temperature. We can observe that the charging efficiency at -20℃ is only 65% of that at 15℃.Low battery temperature brings about changes in the above-mentioned electrochemical properties, and the internal resistance increases significantly. During the discharge process, a large amount of electrical energy is consumed on the internal resistance and generates heat.Lithium battery low temperature preheating technologyFaced with the restrictions on the use of lithium batteries when the battery temperature is low, technicians have found a countermeasure for charging and preheating. Although it is a stopgap measure, it has a significant effect on improving the discharge capacity and long-term life of lithium batteries.Before charging or using lithium batteries in an environment with low battery temperature, the battery must be preheated. The way the battery management system (BMS) heats the battery can be roughly divided into two categories: external heating and internal heating.Compared to external heating methods, internal heating avoids long-path heat conduction and the formation of local hot spots close to the heating device. As a result, internal heating can heat the battery more evenly, resulting in better heating with higher efficiency and is easier to implement.