建筑的電壓監(jiān)測到的能量收集設(shè)計保護鋰離子電池

　　建筑的電壓監(jiān)測到的能量收集設(shè)計保護鋰離子電池

　　鋰離子電池在操作安全和整個電池壽命的考慮下，在一個狹窄的容差范圍內(nèi)工作。確保適當?shù)墓ぷ麟妷核剑?a target='_blank' class='arckwlink_none'>工程師可以建立電壓監(jiān)測功能為能量收集設(shè)計使用包括模擬設(shè)備，ATMEL，集成，Skyworks，意法半導體制造商的各種專用集成電路，德克薩斯文書，其中。

　　李離子電池通常充電的標稱電壓為4.20伏，耐受性約為50毫伏。根據(jù)一個特性充電配置文件（圖1），電池通過恒定電流相達到這個設(shè)定點電壓，快速地產(chǎn)生電荷水平和一個恒定電壓相位，使電池達到最大充電水平。

　　Figure 1： The characteristic constant-current/constant-voltage charging profile for a lithium-ion cell brings a cell to its optimum charge point beyond which application of higher voltage results in cell stress and eventual damage （Courtesy of Texas Instruments）。

　　Although application of higher voltages beyond the 4.2 V set point can temporarily increase cell capacity， higher voltages result in internal changes in the cell. In cells subject to prolonged overvoltage conditions， lithium ions begin to plate on the anode， reducing the number of free lithium ions and resulting in loss of cell-charging capacity and overall cell lifetime. Furthermore， the continued application of voltage levels beyond the set point causes oxidizing effects that result in production of CO2. If overvoltage conditions are allowed to persist， increased CO2pressure can cause the cell‘s internal safety membrane to rupture， risking catastrophic thermal runaway and even combustion.

　　To prevent overvoltage conditions， engineers can select from a range of specialized devices including ICs designed to target typical Li-ion batteries with a limited number of cells， ICs designed for large multi-cell stacks， ICs designed specifically for ambient-energy–harvesting designs， or even software-based solutions using highly integrated MCUs.