Compared with lead-acid batteries, lithium batteries boast advantages such as higher energy density, greater environmental friendliness, and longer service life. At present, the process of lithium batteries replacing lead-acid batteries has been accelerating gradually. In the field of large-scale energy storage, many companies have also independently developed lithium battery energy storage systems. Lithium battery energy storage systems are pollution-free to the environment, and their replacement of lead-acid energy storage technology represents the future direction of the energy storage industry. # Are Lithium Batteries More Environmentally Friendly than Lead-Acid Batteries? After years of sustained development, China's lead-acid battery industry has basically formed its own system and is showing a rapid development trend. It has also made considerable breakthroughs in addressing environmental issues. However, due to factors such as a large number of manufacturers, small production scales, high pollution levels, and inconsistent product quality, the pollution problems arising from the production of lead-acid batteries have not been fully resolved. Particularly, a considerable number of small and medium-sized enterprises have severe pollution issues in their production processes, which have exerted an extremely negative impact on the entire electronics industry. There are various ways to determine whether a product is more environmentally friendly than others. Lithium batteries do not contain harmful substances, whereas lead-acid batteries do (e.g., they contain lead). Both types of batteries are recyclable; however, in most regions around the world, recycling lead-acid batteries used in UPS systems and electric vehicles is far less difficult than recycling large-scale lithium batteries. Pollution from lead-acid batteries mainly occurs during the production process. Heavy metal wastewater containing lead is generated during the plate coating and battery cleaning processes, while various lead-containing fumes and dust are produced during grid casting, alloy preparation, lead part manufacturing, and aluminum powder production. Nevertheless, a comprehensive analysis of environmental impacts requires considering the overall carbon footprint throughout the battery's service life. The carbon footprint accumulates across the entire product lifecycle: - Raw material extraction - Energy consumption in production and transportation - Operational energy consumption required for battery charging and cooling - Reusability and the impact on land during disposal Previous analyses have indicated that, to date, operational losses (i.e., the energy consumption required for battery charging) are the primary contributor to the carbon footprint of UPS systems and their battery systems over a 10-year lifecycle. However, there is no significant difference in operational losses between these two battery systems, and which battery system is superior depends on the specific application scenario. Lithium batteries consume less energy during charging than lead-acid batteries. The charge cycle efficiency of lithium batteries and lead-acid batteries is 90% and 80–85%, respectively. In addition, lead-acid batteries have a higher self-discharge rate than lithium batteries. However, lithium batteries require a Battery Management System (BMS) to prevent short circuits and overcharging, which offsets these efficiency gains. This monitoring system consumes energy. Therefore, the overall operational losses between the two are extremely similar. In addition to identifying the dominant factors affecting the carbon footprint over a 10–15-year period, since both have their respective advantages and disadvantages, other factors must also be taken into account. Given that lithium batteries, which contain materials that can be safely landfilled in garbage dumps, are recyclable and have a service life 2–3 times longer than that of lead-acid batteries, they can be considered "more environmentally friendly". It should be noted, however, that the recycling rate of lead in lead-acid batteries is 99%, with over 90% of used batteries being collected (this is data from North America; Europe and Japan have similar rates). In contrast, the recycling of lithium batteries is far from mature, especially for large-scale lithium batteries (e.g., those used in electric vehicles and data center UPS systems). From a technological upgrading perspective, lithium batteries have advantages such as high specific energy, long service life, and environmental friendliness. With the further development of the battery industry, they are bound to replace lead-acid batteries, which is an inevitable trend in industrial development. In terms of economy, considering the entire battery lifecycle, lithium batteries have a longer service life, and their average usage cost is not much higher than that of lead-acid batteries. In any case, lithium batteries still cause some pollution, albeit relatively less. We all live on the same planet, so environmental awareness must start with ourselves. Moreover, waste batteries should not be mixed with other types of household waste but should be disposed of separately. The call for waste battery recycling has been around for a long time. Generally, dry batteries contain heavy metals, which are toxic and can seriously harm the environment and human health. People need to cultivate environmental protection awareness; only when everyone takes action can we make an impact and drive the active development of related environmental protection industries. Lithium battery manufacturers must not only pay attention to the purification treatment of process waste during production but also significantly improve the pollution control technologies for discarded batteries. # Conclusion Compared with traditional lead-acid batteries, lithium batteries have numerous advantages, including small size, light weight, high operating voltage, large specific energy, long cycle life, non-pollution, and good safety performance. Therefore, as the production of lead-acid batteries becomes unsustainable, lithium batteries will benefit more from the current round of environmental inspections, emerge as a market favorite, and become highly sought-after battery products in the market.