Piezoelectric Energy Harvesting Devices: An Alternative Energy Source for Wireless Sensors

Table 5

Characteristics of Li-ion, thin film batteries [57].

Characteristic	Battery		Supercapacitor
	Li-ion	Thin film
Operating voltage (V)	3–3.70	3.70	1.25
Energy density (W h/l)	435	<50	6
Specific energy (W h/kg)	211	<1	1.5
Self-discharge rate (%/month) at 20°C	0.1–1	0.1–1	100
Cycle life (cycles)	2000	>1000	>10,000
Temperature range (°C)	−20/50	−20/+70	−40/+65