Lead-Acid Batteries
Lead-acid batteries are chemical energy storage devices. They use lead and lead dioxide (PbO₂) as the active materials for the negative and positive electrodes, with dilute sulfuric acid as the electrolyte. Essentially, they convert electrical energy to chemical energy and vice versa through electrochemical reactions. These batteries are the top choice for various energy storage systems, emergency power supplies, and soft/black start devices.
A single-cell lead-acid battery has a nominal voltage of 2.0V. It can discharge down to 1.5V and charge up to 2.4V. In practical applications, six single cells are often connected in series to form a 12V nominal lead-acid battery module. On this 12V basis, appropriate series and parallel connections can be made to achieve the voltage level required by the system—such as 48V or 96V—enabling normal charging and discharging operations.
Lead-acid batteries mainly fall into three categories: general flooded lead-acid batteries, gel maintenance-free batteries (designed specifically for solar energy systems), and lead-carbon batteries. In real-world use, the share of gel batteries and lead-carbon batteries is growing steadily. Gel batteries offer better over-discharge tolerance, self-recovery capability, and charge-discharge performance at low temperatures. Lead-carbon batteries add carbon (graphene) to the electrolyte. This addition prevents the sulfation of the negative electrode, addressing the common issue of premature battery failure and significantly extending the battery’s service life.
Lithium Batteries
Lithium batteries are a type of battery that uses lithium metal or lithium alloys as anode or cathode materials, paired with non-aqueous electrolyte solutions. They are mainly divided into two types: lithium metal batteries and lithium-ion batteries. The term “lithium battery” in everyday use usually refers to lithium-ion batteries. These are rechargeable secondary batteries. Lithium-ion batteries adopt lithium alloy metal oxides as the cathode material and graphite as the anode material. The anode material acts as the host for lithium storage. It plays a key role in determining the battery’s charge-discharge efficiency, cycle life, and other core performance metrics.
Based on different cathode materials, lithium-ion batteries can be further categorized into several types. The main ones include lithium cobalt oxide batteries, lithium manganese oxide batteries, lithium nickel oxide batteries, lithium iron phosphate batteries, and ternary lithium batteries.