Noun explanation

Statistical percentile calculation is a data analysis method used to divide a set of data into several percentage segments and identify its position in the overall distribution. For example, the 90th percentile indicates that 90% of the data values are below this value.

In the battery industry, this method is widely used in the following scenarios:

Quality control: By analyzing the distribution of parameters such as battery capacity, internal resistance, and lifespan, abnormal cells can be identified or consistency can be evaluated.

Life assessment: In a large amount of battery degradation data, the lifespan performance under the

Supercapacitors, also known as double-layer capacitors or electrochemical capacitors, are a type of energy storage device that lies between traditional capacitors and chemical batteries, with the following characteristics:

High power density (fast charging and discharging)

Ultra-long cycle life (up to one million cycles)

Good low-temperature performance

Low energy density (compared to batteries)

In battery systems, supercapacitors are usually used for:

Auxiliary starting: supporting the instantaneous high current start-up of electric vehicles

Brake energy recovery: quickly absorbing and releasing energy to improve system efficiency

Extending battery life: mitigating the load impact on the main battery and reducing its aging speed

Surplus energy refers to the excess electricity that is not consumed when the power generation exceeds the current load demand, which is common in renewable energy systems such as wind and solar energy. In the battery industry, the utilization of surplus energy is directly related to: the design capacity of energy storage systems: energy storage systems need to have sufficient capacity to absorb surplus energy to avoid the phenomenon of ‘waste of wind and light’. Peak shaving and valley filling strategy: store the surplus energy during the off-peak period and release it during the peak electricity consumption period to achieve grid balance. Economic benefit improvement: by capturing surplus energy through energy storage systems and selling electricity or using it for other loads, maximum revenue can be achieved.

Sustainability in the battery industry is a comprehensive evaluation dimension that covers the entire product life cycle, including:
Resource availability: for example, whether lithium, cobalt, and other key metals are easily obtainable and whether they are substitutable
Carbon footprint of the manufacturing process: whether there are carbon reduction measures in high-energy-consuming processes such as high-temperature sintering and metal extraction
Recycling and reuse: the recycling efficiency and material regeneration capacity after the battery has served its purpose
Social and policy responsibility: whether it meets international environmental regulations and fair trade standards
Achieving the goals of sustainable development (such as the EU Battery Regulation) has become a necessary condition for the compliance and competition of the battery industry chain.

System design refers to the full-process integrated planning for a battery system (such as an electric vehicle battery pack, energy storage system), covering the following aspects: cell selection and configuration: such as the number of series and parallel connections, capacity matching; thermal management system: design of air cooling, liquid cooling, or phase change materials; BMS integration: integration of voltage, current, temperature, and communication control logic; safety protection mechanisms: protection against overcharging, over-discharging, short-circuit, and other protection; mechanical structure and packaging design: to meet the requirements of shock resistance, waterproofing, and fireproofing.

The Swelling Force Model is used to quantitatively describe the mechanical stress caused by the volume change of active materials during the charging and discharging process of batteries, which is particularly important for: the negative electrode materials of lithium-ion/sodium-ion batteries (such as silicon, tin): their volume expansion during charging can reach several times; structural simulation of soft-pack batteries: predicting whether the packaging film can withstand internal pressure; module/cell design: helping to set appropriate pre-tension and buffer structures to avoid bulging, cracking, or failure.

System design refers to the full-process integrated planning for a battery system (such as an electric vehicle battery pack, energy storage system), covering the following aspects: cell selection and configuration: such as the number of series and parallel connections, capacity matching; thermal management system: design of air cooling, liquid cooling, or phase change materials; BMS integration: integration of voltage, current, temperature, and communication control logic; safety protection mechanisms: protection against overcharging, over-discharging, short-circuit, and other protection; mechanical structure and packaging design: to meet the requirements of shock resistance, waterproofing, and fireproofing.

System downtime refers to the total time that the battery system is stopped from operating due to unplanned events (such as failures, anomalies, etc.) or planned maintenance. In the battery industry (especially in scenarios such as energy storage power stations, data center UPS, electric vehicles, etc.), the shorter the downtime, the higher the system availability and economic efficiency. Strategies to reduce downtime include: high-reliability component selection, redundant design (such as backup battery packs), fault prediction and early warning systems (such as SoH tracking), and quick repair and modular replacement design.

System performance is a measure of the overall efficiency of a battery system (such as energy storage systems, battery packs for electric vehicles, etc.) under real operating conditions. It mainly includes the following aspects:

Energy Efficiency (Round-trip Efficiency): The proportion of energy loss in the charging and discharging processes;

Power Performance: The response speed of the system to the load and the maximum output power;

Reliability and Stability: The failure rate and available time during long-term operation;

Thermal Performance and Environmental Adaptability: The ability to maintain performance under different temperature and humidity conditions.

In practical applications: The system performance of electric vehicles determines their range, safety, and driving experience; in the field of energy storage, system performance affects economic benefits and scheduling capabilities.

The temperature boundaries are the safe temperature range allowed for the operation of the battery system, which is usually specified by the cell manufacturer or system designer. For example, the operating temperature of a typical lithium-ion battery is as follows:

Charging: 0℃ ~ 45℃

Discharging: –20℃ ~ 60℃

Exceeding the temperature boundaries may cause:

Electrolyte decomposition
SEI film breakdown
Material structure damage
Thermal runaway

Thermal management is a technical means to control the temperature of the battery system within a safe and efficient range, covering measures such as heat dissipation, insulation, and refrigeration.

In the role of the battery industry: During the charging and discharging process of batteries, heat is generated. If not controlled in time, it will lead to performance degradation, accelerated aging, and even thermal runaway. The thermal management system ensures uniform temperature distribution, enhancing lifespan and safety.

Thermal mass refers to the ability of an object or system to absorb, store, and release thermal energy. It reflects the thermal inertia of the material in the process of temperature change, that is, the ‘slowness’ of heating up or cooling down.
In the battery system, thermal mass determines the response speed of the battery to temperature changes, directly affecting battery safety, thermal management system design, and risk control of thermal runaway.
The main functions include:

Buffering temperature changes: Materials with high thermal mass can slowly increase in temperature when the battery is subjected to thermal shock, which helps to delay the occurrence of thermal runaway;

Improving system thermal stability: It can reduce the temperature difference inside the battery, improve the uniformity of temperature distribution;

Influencing cooling/heating strategies: Systems with high thermal mass are more difficult to heat up or cool down, requiring the thermal management system to output greater power or preheat in advance;

Determining the rate of heat diffusion: It, together with thermal conductivity, affects the heat diffusion behavior between modules/packages.

A thermal model is a mathematical model that describes the temperature changes and heat transfer behavior of batteries under different working conditions.

In the role of the battery industry:
Thermal models are used to predict temperature distribution, optimize thermal management systems, and prevent local overheating and thermal runaway.

Thermal propagation refers to the process of heat conduction from one cell to adjacent cells or modules.

In the battery industry, its role is as the main mechanism of the thermal runaway chain reaction in battery packs, which is directly related to system safety.
Factors: cell spacing, material thermal conductivity, structural ventilation;

Batteries undergo self-heating reactions under conditions such as overheating and overcharging, leading to a continuous rise in temperature and potentially causing combustion or explosion.

In the role of the battery industry: It is one of the most critical risk factors for battery safety and must be prevented through structural, thermal management, and control strategies.
Trigger reasons: lithium dendrite piercing, internal short circuit, external overheating;

Titanium is a lightweight, high-strength, and corrosion-resistant metal material, which is sometimes used in electrodes or structural components.

In the battery industry, its role includes: acting as an anode material in some lithium titanate batteries, with high safety and long life characteristics; it is also used in battery shell structures, connecting strips, and so on.

Transition Metal Dissolution refers to the phenomenon that during battery operation or storage, transition metal elements (such as Mn, Ni, Co, Fe, etc.) in the positive electrode material are separated from the positive electrode, enter the electrolyte and may migrate to the surface of the negative electrode.

This is an irreversible degradation reaction that usually occurs under conditions of high temperature, high voltage, or side reactions between the electrolyte and the positive electrode material.

Trend analysis is to identify the trend and development direction of variables over time through statistical, modeling, and graphical analysis of historical data series.
It is used to identify the changes of battery performance parameters (such as capacity, internal resistance, temperature, cycle life, etc.) with time or charge-discharge cycles, identify potential problems in advance, optimize manufacturing processes, and formulate predictive maintenance strategies.

Battery underperformance refers to the failure of batteries to meet the expected technical or commercial performance indicators during actual operation, such as capacity, power, and lifespan.

The role of underperformance in the battery industry:
Underperformance directly affects the reliability and market acceptance of products, and is a key focus for quality management, after-sales service, and product development optimization.