What Are The Differences Between Lithium Batteries With Different Discharge Rates?
1. Electrode materials and structures
Active material characteristics: For example, lithium iron phosphate (LFP) is suitable for low rates but long life, while ternary lithium (NCM/NCA) supports high rates but has low cycle stability.
Electrode thickness and porosity: Thin electrodes (such as <100μm) can shorten the lithium ion diffusion path and support high rates; high porosity (such as 40%-50%) enhances electrolyte wetting and reduces polarization.
2. Battery Electrolyte and diaphragm
Electrolyte formula: High dielectric constant solvents (such as EC) increase ion dissociation, but have higher viscosity; additives (such as FEC) can stabilize the SEI film and improve high-rate cycle performance.
Diaphragm pore size and wettability: Small pore size (such as <10nm) can suppress dendrites, but may increase ion transmission resistance; ceramic-coated diaphragms can improve heat resistance and support high-rate discharge.
LiFePO4 Electrolyte
3. Battery design and process
Pole ear layout: Multi-pole ear or edge current collection design can reduce ohmic resistance and support higher rates.
Package density: Too high compaction (such as >2.4g/cm³) may block ion channels; too low will increase electrode volume and reduce energy density.
Packaging pressure: Insufficient packaging pressure of soft-pack batteries may cause electrode dislocation and increase contact resistance.
4. Thermal management and heat dissipation
Specific surface area: Small-sized batteries (such as 18650) have large specific surface area and fast heat dissipation, which can support higher instantaneous rates; square batteries need to rely on heat sinks or liquid cooling.
Operating temperature: At low temperatures (such as -20℃), the electrolyte ion conductivity drops by 3-4 orders of magnitude, resulting in a sharp drop in the available discharge rate.
5. Battery management system (BMS)
Protection threshold: BMS may limit the maximum discharge current (such as 10C protection) to prevent overheating or overvoltage, even if the battery theory supports a higher rate.
SOC estimation accuracy: The internal resistance increases significantly at low SOC, and the BMS may dynamically adjust the allowable discharge rate to avoid voltage drop.
16s 100A 48V BMS For Lifepo4 Battery
6. Cycle aging state
SEI film thickening: The resistance of the negative electrode SEI film increases after cycling, resulting in increased polarization during high-rate discharge.
Active material shedding: High-rate cycling may accelerate electrode pulverization and reduce the effective reaction area.

Even if the materials are the same, the discharge rate of lithium batteries is still subject to multiple constraints such as electrode engineering, electrolyte optimization, thermal management design, BMS strategy and aging status. High-rate batteries need to sacrifice some energy density and life, and improve power performance through refined structural design (such as nano-electrodes, gradient pore distribution) and process control (such as vacuum coating, laser welding).
Acey New Energy is a high-tech enterprise. Our R&D team specializes in researching and manufacturing high-end equipment for lithium-ion batteries. Our business covers semi-automatic & fully automatic assembly machines for cylindrical, prismatic, and pouch battery packs; battery cell & pack testing systems; lab-scale fabrication machines for coin cells, cylindrical cells, and pouch cells; battery environmental safety testing equipment; battery materials; and supercapacitor production equipment, etc.