리튬 2차전지란?

리튬 2차전지는 리튬 이온을 활용한 재충전 가능한 배터리로, 이차전지(보조전지)의 한 종류입니다. 리튬 2차전지는 전기차, 스마트폰, 노트북, 전자기기 등 다양한 분야에서 에너지 저장 장치로 널리 사용되고 있습니다.

리튬 2차전지는 주로 리튬 이온 전지(Li-ion)를 의미하며, 이 전지는 음극과 양극 사이에 리튬 이온이 이동하면서 전기 에너지를 저장하고 방출합니다. 충전 과정에서 리튬 이온은 양극(대부분 흑연 또는 실리콘 기반)에서 음극(일반적으로 리튬 코발트 옥사이드, 리튬 망간 옥사이드, 리튬 철 인산염 등)으로 이동하고, 방전 과정에서는 반대 방향으로 이동합니다.

리튬 2차전지는 다음과 같은 특징을 가지고 있습니다:
1. 높은 에너지 밀도: 무게 당 저장할 수 있는 에너지량이 크기 때문에, 작고 가벼운 배터리로도 높은 용량을 달성할 수 있습니다.
2. 낮은 자체 방전률: 저장된 전기 에너지가 시간이 지나면서 점차 소모되는 현상인 자체 방전률이 낮아, 장기간 사용이 가능합니다.
3. 긴 순환수명: 충전과 방전을 반복할 수 있는 횟수가 많아, 오랫동안 사용할 수 있습니다.

하지만 리튬 2차전지는 과열 및 과충전 등에 의해 화재 또는 폭발 위험이 존재하므로, 관리와 보호 회로 설계에 주의를 기울여야 합니다. 이러한 문제를 해결하기 위해 리튬-인산철 전지, 리튬-황 전지, 리튬-공기 전지 등의 새로운 리튬 2차전지 기술들이 연구 및 개발되고 있습니다.

 

A lithium rechargeable battery is a rechargeable battery utilizing lithium ions and is a type of secondary battery (rechargeable battery). They are widely used as energy storage devices in a variety of applications, including electric vehicles, smartphones, laptops, and electronic devices.

Lithium secondary batteries primarily refer to lithium-ion (Li-ion) cells, which store and release electrical energy as lithium ions move between the cathode and anode. During the charging process, lithium ions move from the anode (mostly graphite or silicon-based) to the cathode (usually lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, etc.), and during the discharging process, they move in the opposite direction.

Lithium secondary batteries have the following characteristics
1. high energy density: the amount of energy that can be stored per weight is large, so even small and light batteries can achieve high capacity.
2. Low self-discharge rate: The self-discharge rate, a phenomenon in which stored electrical energy is gradually consumed over time, is low, allowing for long-term use.
3. Long cycle life: The number of times they can be charged and discharged repeatedly is high, allowing them to be used for a long time.

However, lithium secondary batteries are at risk of fire or explosion due to overheating and overcharging, so careful management and protection circuit design are required. To address these issues, new lithium secondary battery technologies such as lithium-iron phosphate batteries, lithium-sulfur batteries, and lithium-air batteries are being researched and developed.