Nickel-metal hydride (NiMH) is a type of rechargeable battery that uses nickel oxide hydroxide and a hydrogen-absorbing alloy as its electrodes. It is known for its higher energy density compared to traditional nickel-cadmium (NiCd) batteries, making it suitable for various applications, including portable electronics and hybrid vehicles. NiMH batteries are environmentally friendly, as they do not contain toxic heavy metals like cadmium. They offer good performance in terms of charge capacity and can be recharged hundreds of times, making them a popular choice for devices such as digital cameras and power tools.