Lithium-ion batteries present notable advantages in the realm of electric vehicles. Their volume-to-energy and weight-to-energy ratios surpass those of lead-acid batteries by more than three times, resulting in smaller and lighter batteries. Furthermore, they offer a longer cycle life, which is a crucial factor in determining battery performance.
When considering the distance an electric vehicle can travel, battery capacity plays a pivotal role. It is insufficient to merely state which type of battery provides greater range without taking capacity into account. For example, if both batteries are rated at 48V20AH, lithium-ion and lead-acid batteries will exhibit similar performance due to their identical capacity. However, the lighter weight of lithium-ion batteries may slightly extend their range compared to lead-acid batteries under identical conditions. Conversely, if a lithium-ion battery is rated at 48V10AH and a lead-acid battery is rated at 48V20AH, the lead-acid battery will undoubtedly have a greater range due to its higher capacity. Ultimately, the battery with the larger capacity will travel farther.
Despite their advantages, lithium-ion batteries also pose certain concerns, particularly when connected in series with high capacity. Safety becomes a paramount issue, as mobile phone batteries have occasionally exploded, highlighting the potential risks. Although lead-acid batteries are bulkier, they offer significantly greater stability and safety than lithium-ion batteries. Additionally, lead-acid batteries are more cost-effective and widely accepted in the market. In terms of stability, safety, and cost, lead-acid batteries have an edge over lithium-ion batteries. However, it is worth noting that both types of batteries are considered heavily polluting.
Currently, the market inventory of lead-acid batteries for electric vehicles remains higher than that of lithium-ion batteries, potentially due to the higher cost of lithium-ion batteries. To reduce overall vehicle costs, manufacturers often decrease the capacity of lithium-ion batteries in existing electric vehicle designs, resulting in limited model variety. Lead-acid and lithium-ion batteries each have their own strengths and weaknesses, catering to different consumer groups. Presently, lithium-ion batteries are predominantly used in electric bicycles with limited range. However, for longer-range models, such as four-wheel electric vehicles and elderly electric scooters, lead-acid batteries are more suitable based on current technology.
Lithium ions function primarily by moving between the positive and negative electrodes during charging and discharging. During charging, lithium ions are deintercalated from the positive electrode and intercalated into the negative electrode through the electrolyte, making the negative electrode lithium-rich. The opposite occurs during discharging. Batteries typically use lithium-containing materials as electrodes, with graphite being the most common negative electrode material. Compared to lead-acid batteries, lithium-ion batteries offer lighter weight, larger specific capacity, and longer cycle life. As a power source for elderly electric scooters, lithium-ion batteries provide lightweight, portable convenience and contribute to the “lightweight and simplified” design of vehicle products.
Lead-acid batteries consist of electrodes primarily made of lead and its oxides, with sulfuric acid solution serving as the electrolyte. In a charged state, the positive electrode’s main component is lead dioxide, while the negative electrode’s main component is lead. In a discharged state, both electrodes’ primary component is lead sulfate. Despite both being energy storage devices, these two types of batteries differ significantly in terms of safety, cost, and energy density.
Lead-acid batteries offer superior safety and lower cost but have lower energy density compared to lithium-ion batteries, resulting in a larger volume. Currently, before breakthroughs in battery technology research occur—specifically, the commercial practical application of “low-cost, high-performance” batteries—combining and upgrading the excellent characteristics of existing lead-acid and lithium-ion batteries should be the primary research focus for the current and future periods. This approach provides a clearer direction for the future development of elderly electric scooters and even the entire electric scooter industry.
Lead-acid batteries are commonly used in electric vehicles primarily due to their high cost-effectiveness. In terms of endurance, with all other conditions being equal and battery capacity being the same, lithium-ion batteries may offer slight advantages due to their lighter weight, which reduces the overall vehicle weight and potentially enhances range.
However, I still recommend lead-acid batteries for the following reasons:
- Affordability: Typically, a set of lead-acid batteries costs only a few hundred yuan, whereas a set of lithium-ion batteries costs between one thousand to two thousand yuan.
- Safety: Incidents of lithium-ion electric bikes exploding due to overheating, such as the case of a woman in Nanjing, highlight the potential risks associated with lithium-ion batteries.
- Sufficiency: Current lead-acid batteries generally offer a range of 50-60 kilometers, which is sufficient for household use. Lithium-ion batteries may be unnecessary for such applications.
In conclusion, while lithium-ion batteries offer several advantages, including lighter weight, larger specific capacity, and longer cycle life, lead-acid batteries remain a popular choice due to their affordability, safety, and sufficient range for many household applications. Consumers can purchase high-quality batteries from reputable manufacturers based on their specific needs and preferences.
The machinery utilized in the manufacturing of lithium batteries is not only costly but also highly valuable, accompanied by substantial depreciation and losses. In contrast to lead-acid batteries, which can be repaired and reused, lithium batteries are largely non-reversible during production. Furthermore, lead-acid batteries exhibit a recycling value exceeding 40% after use, whereas lithium batteries offer negligible recycling value.
Lithium batteries boast a volume-to-energy ratio and weight-to-energy ratio that surpass lead-acid batteries by over three times. Consequently, lithium batteries are more compact and lighter in weight. They also possess a prolonged cycle life. For instance, lithium batteries employed in electric vehicles typically endure over 800 cycles, while those utilizing lithium iron phosphate cathode materials can reach approximately 2000 cycles—a lifespan 1.5 to 5 times longer than lead-acid batteries. This significantly minimizes the operational cost of lithium batteries, extends their durability, and enhances their usability. Additionally, lithium batteries exhibit a broad range of charging efficiency, which is a unique advantage. When necessary, the charging duration can be confined to 20 minutes to 1 hour, achieving a charging efficiency of over 84%. With further technological advancements, this characteristic will be even more effectively harnessed.
Currently, lithium batteries generally possess an energy density ranging from 200-260 Wh/g, whereas lead-acid batteries typically fall between 50-70 Wh/g. This indicates that the weight energy density of lithium batteries is 3-5 times that of lead-acid batteries. Consequently, under identical capacity, lead-acid batteries weigh 3-5 times more than lithium batteries. Hence, in the realm of lightweight energy storage devices, lithium batteries hold an unmistakable advantage.
