Based on the same energy capacity (1 kWh): Analysis of the key differences between ternary lithium, lithium iron phosphate and lead-acid batteries, and their suitability for different applications
Foreword
“In the fields of energy storage, personal mobility and domestic power reserves, batteries are the core component, and ‘1 degree of electricity (1 kWh)’ is the most intuitive and universal standard for measuring a battery’s energy storage capacity. When selecting batteries, many users focus solely on price, yet overlook the significant differences in volume, weight, lifespan, safety and running costs between ternary lithium-ion batteries, lithium iron phosphate batteries and lead-acid batteries, even when they offer the same storage capacity of 1 kWh. These three types of batteries cover the full spectrum of applications, ranging from low-end domestic use and mid-range personal mobility to high-end energy storage and new energy vehicles.”
To present the differences clearly and intuitively, we first organise a comprehensive comparison of the parameters of the three battery types based on a storage capacity of 1 kWh, covering key dimensions such as hardware characteristics, operational performance, economic costs and safety attributes:
| Comparison Dimension | Lead-acid Battery | Lithium Iron Phosphate Battery | Ternary Lithium Battery |
|---|---|---|---|
| Weight & Volume for 1 kWh | Largest volume and heaviest weight; around 8–10 kg per 1 kWh, occupies much space | Medium volume and light weight; around 3–4 kg per 1 kWh, good compactness | Smallest volume and lightest weight; around 2–2.5 kg per 1 kWh, best portability |
| Cycle Service Life | Shortest, 300–500 complete charge-discharge cycles; obvious attenuation after 1–2 years of use | Relatively long, 2000–4000 cycles; stable service for 6–8 years under normal use | Medium, 1000–2000 cycles; high-end versions up to 2500 cycles; usable for 3–5 years |
| Energy Density | Very low, only 30–50 Wh/kg | Medium, 120–180 Wh/kg | Very high, 200–300 Wh/kg, around 6 times that of lead-acid battery |
| Safety Performance | Very high; high temperature resistant, free from explosion; risks are liquid leakage and bulging, no fire hazard | Excellent thermal stability; hard to catch fire or explode under puncture or high temperature | Ordinary; prone to thermal runaway, fire or explosion under high temperature, puncture or short circuit |
| Charge & Discharge Characteristics | Slow charging, fast charging unsupported; unstable discharge performance; severe capacity attenuation at low temperature | Supports fast charging, stable discharge; weak low-temperature performance; over 40% capacity attenuation at -20℃ | Powerful fast charging capacity, high discharge efficiency; best low-temperature performance; retains over 70% capacity at -20℃ |
| Unit Cost (1 kWh) | Lowest production cost, optimal short-term cost performance | Medium manufacturing cost, lowest long-term use cost | Highest cost due to expensive raw materials, high initial investment |
| Maintenance Requirement | Regular maintenance needed; vulnerable to sulfation and damage caused by power depletion; easy to fail if left unused | Maintenance-free; tolerant to standing storage and power depletion, suitable for long-term standby | Maintenance-free, but sensitive to overcharging and over-discharging; store at half charge when idle |
Lead-acid batteries: low-cost, entry-level energy storage; the preferred choice for short-distance, low-speed applications
However, their shortcomings are also very pronounced. For the same energy storage capacity of 1 kWh, lead-acid batteries are heavy and bulky, offering extremely poor portability, and cannot be used in devices with space or weight constraints. Furthermore, their service life is extremely short, with fewer than 500 charge cycles; in everyday use, their capacity declines significantly within 1–2 years, and they are essentially completely worn out after 3 years.
Furthermore, lead-acid batteries charge slowly and do not support high-current fast charging. Their energy storage capacity drops dramatically in low-temperature environments, with range loss exceeding 50 per cent in winter. Prolonged inactivity also leads to plate sulphation, which directly results in the battery becoming unusable.
Their suitability is highly limited; they are only suitable for low-cost, low-range, fixed-location, low-speed equipment. The most common applications include standard two-wheeled electric bicycles, electric tricycles, UPS backup power supplies, street lighting energy storage and small domestic backup power supplies – scenarios where weight and service life are not critical and budget constraints are the primary consideration. Lead-acid batteries are entirely unsuitable for high-frequency use, long-range applications or mobile energy storage scenarios.
Lithium iron phosphate batteries: long-lasting and highly safe, the mainstream choice for domestic energy storage
For the same energy storage capacity of 1 kWh, its weight and volume are only about one-third that of a lead-acid battery, significantly enhancing portability whilst completely eliminating the short lifespan associated with lead-acid batteries. With a cycle life of over 8,000 cycles, the battery can be used reliably for 6–8 years under normal daily charging and discharging conditions, requiring virtually no replacement, and offers far better value for money over the long term than lead-acid batteries.
Safety is the key competitive advantage of lithium iron phosphate batteries. With a thermal runaway temperature as high as 800°C, they offer exceptional resistance to high temperatures, impact and puncture. They will not catch fire or explode in the event of a short circuit or when exposed to high temperatures, making them the safest type of lithium battery for domestic energy storage. They also support high-current fast charging, boast high charge and discharge efficiency, and achieve an energy utilisation rate of over 95 per cent. Furthermore, they are maintenance-free and tolerant of prolonged inactivity; they do not lose charge or sulphate when stored for long periods, making them suitable for long-term standby energy storage applications.
The main disadvantage of these batteries lies in their low-temperature performance; capacity degradation is significant in extremely cold conditions, with storage capacity reduced to around 60 per cent at –20°C, rendering them unsuitable for extremely cold outdoor environments in northern regions. Furthermore, their energy density is lower than that of ternary lithium batteries; for the same capacity, they are slightly larger and heavier than ternary lithium batteries, making them unsuitable for equipment requiring extreme lightweight design.
They are primarily suited to applications involving normal temperatures, long-term use, and fixed or semi-mobile energy storage scenarios, including domestic photovoltaic energy storage systems, outdoor power banks, new energy buses, power supplies for construction equipment, low-speed new energy vehicles, and backup power supplies for base stations. They currently represent the optimal solution for civilian energy storage and mid-range personal mobility devices.
Ternary lithium-ion batteries: high energy density and lightweight, designed exclusively for high-end mobile devices
At the same time, they offer the best charge and discharge performance, the fastest charging speed and the highest energy utilisation rate. Their low-temperature performance far surpasses that of lithium iron phosphate batteries; they retain over 70 per cent of their storage capacity even in the harsh cold of -20°C, ensuring exceptional range stability throughout the year.
In terms of user experience, ternary lithium batteries deliver a linear and stable discharge curve with powerful power output, making them ideal for mobile devices with extremely high demands for power, range and lightweight design. Although their cycle life is not as long as that of lithium iron phosphate batteries, it far exceeds that of lead-acid batteries; under normal use, there is no significant degradation over 3–5 years, meeting the service life requirements of high-end devices.
Their key shortcomings lie in safety and cost. Ternary materials have poor thermal stability and can undergo thermal runaway at around 200°C; when subjected to puncture, severe impact or short circuits, they are highly prone to catching fire or even exploding, posing relatively high safety risks. Furthermore, the cost of raw materials is high; for the same energy storage capacity of 1 kWh, the manufacturing cost is the highest among the three battery types, resulting in initial investment costs that are significantly higher than those of the other two types. In addition, ternary lithium-ion batteries are susceptible to overcharging and over-discharging, placing extremely high demands on protection circuits and requiring even greater precision in maintenance.
📄Summary
Taking a comprehensive comparison, there is no absolute superiority or inferiority amongst the three types of batteries; it is simply a matter of suitability for different scenarios. Assuming the same energy capacity of 1 kWh, lead-acid batteries excel in their extremely low price and absolute safety, making them suitable for short-term, infrequent and low-cost basic applications; lithium iron phosphate (LFP) batteries excel in their long service life, high safety and cost-effective long-term use, making them the best value-for-money option for domestic energy storage and consumer electronics; ternary lithium batteries excel in their lightweight design, high energy efficiency and all-weather adaptability, making them the exclusive choice for high-end mobile devices.
When making a purchase, ordinary users should consider the following: for short-distance travel or simple backup power with a limited budget, lead-acid batteries are a suitable choice; for long-term stability, safety and durability—such as home solar energy storage or everyday outdoor power needs—LFP batteries should be the first choice; and for situations requiring extreme portability, long-range endurance, use in extremely cold regions or as a component for high-end equipment, ternary lithium batteries are the most appropriate option. Only by selecting the battery that precisely matches your specific use case can you maximise its energy storage value and minimise long-term running costs.
