The Basic Principle of Rechargeable Batteries — The Bidirectional Journey of Electrical And Chemical Energy

Our lives have long been surrounded by rechargeable batteries: mobile phones, computers, electric vehicles, smart homes, and even space probes all rely on this device that can repeatedly "store" and "release" electrical energy. Unlike disposable batteries that are "discarded after use", the core advantage of rechargeable batteries is to realize the two-way conversion between electrical energy and chemical energy, thereby achieving the purpose of recycling.

Its working principle is essentially the "reversibility of redox reactions": when the battery is charged, an external power supply provides electrical energy, forcing the active substances inside the battery to undergo a "reverse reaction", converting electrical energy into chemical energy and storing it inside the battery; when the battery is discharged, the internal chemical energy is spontaneously converted into electrical energy to supply power to external devices, and a "forward redox reaction" occurs at this time.

Simply put, a rechargeable battery is like an "electrical energy reservoir": when charging, it is equivalent to filling water into the reservoir (storing energy); when discharging, it is equivalent to releasing water from the reservoir (releasing energy). This "reservoir" can be filled and drained repeatedly, and as long as the internal structure is not damaged, it can continue to function. Common rechargeable batteries, regardless of type, basically consist of four parts: positive electrode, negative electrode, electrolyte and separator, which work together to ensure the smoothness and safety of energy conversion.