能源收集存儲選項：可充電電池，超級電容器，或兩者兼而有之？

　　當能量源不穩(wěn)定且不可預測時，能量收集也許更精確地稱為“能量清除”——這是一種越來越可行的供電方式，而無需提供外部電源或定期更換電池。這實際是由多種因素造成的：更好的儲能元件，改進的電源管理組件，并可以操作和執(zhí)行有用的功能電路，如記錄和報告使用無線只是微安和毫瓦的功率數(shù)據(jù)。

　　能量收集系統(tǒng)由四個主要功能組成：一個能量源（換能器），一個儲能元件，一個啟動過程中的整體管理控制器，收獲，操作模式（通常是重疊的）；以及負載本身（圖1）。我們來看看最常見的兩種儲能元件：可充電電池（在大多數(shù)情況下，鋰化學變化）和超級電容器（也稱為超級電容和超級電容，雖然正式名稱是雙電層電容器）。

　　Figure 1： Four functional elements are common to all energy-harvesting designs： the source transducer， the energy-storage element， the load， and a system controller or power-management unit.

　　Both are good options， but they have some operational differences with respect to capacity/power and energy density， charge/discharge cycles， discharge depth， form factor， ruggedness， load transient performance， lifetime， and cost. How you assess and weight these parameters depends， of course， on your application specifics， priorities， and constraints.

　　An important caution to keep in mind： the terms “energy” and “power” are both used in energy-harvesting applications. They are intimately related， of course： power is the rate which energy is being used （work is being done）， and energy is the time-integral of power—but depending on your application and which part of its operational cycles you are at， you may be more interested in one than the other. So be careful in your use of these words， and be sure you know which one you really are concerned with at any given instant.