摘要或動機

伏打電池中，若兩極的電極種類及溶液種類均相同，僅是兩極的溶液濃度或溶液溫度不同，兩極間就有電位差，稱為濃差電池及溫差電池。典型的濃差電池中 ( 電極為電解液正離子的金屬片
)，濃度大的一端電位較高，電池電壓與兩杯溶液濃度比值的對數值成正比，且在相同濃度比值時，硝酸銀濃差電池的電壓最大，其次為硝酸銅、硫酸銅，硫酸鋅濃差電池的電壓最小。硫酸銅溫差電池，若電極為銅片，則電池電壓與兩杯溶液溫度差成正比，且溫度高的一端電位較高。

我們將硫酸銅溫差電池製成太陽能電池，在太陽下曝曬3 小時，電壓可達 13.6mV， 電流可達0.76mA，因此只要串聯數個電池以提高電壓，再對鉛蓄電池充電，就可以達到方便、實用與重複使用的目的。

In a voltaic cell, if the kinds of both electrodes and electrolytes are the same,
but the molality or the temperature of the solutions are different, there will be
potential difference between the two electrodes. We can them molality-difference
cells and temperature-difference cells. In a typical molality-difference cells－its
electrode is a piece of metal which is the same kind of metal with the cation electrolyte.－the
electrode with the higher molality has the higher potential, and the potential and
the log of the fraction of the molality of the two glasses of solution are directly
proportional, and when the fraction is the same, AgNO₃ has the highest potential
and then Cu(NO₃)₂ and CuSO₄, and ZnSO₄ has the lowest potential. In a CuSO₄ temperature-difference
cell, if its electrode is a piece of cuprum, then the potential and the temperature-
difference of the two glasses of electarolytes are directly proportional, and the
electrode with the higher temperature has higher potential.



We use CuSO₄ temperature
cell to make a solar cell, and put it under the sun for 3 hours, the potential can
be 13.6 m V, and the current can be 0.76m A. Therefore we can make several of them
series to get higher potential and charge a lead storage battery. By this way, we
can make a convenient, practical and recycled battery.