For the first time, a small organic molecule of 2,2’,5,5’-tetrahydroxybiphenyl (BP4OH) is synthesized as a new organic cathode for Li-ion batteries. After setting reduction in the 1^st cycle in Li-ion half cells (reduction→oxidation), BP4OH can be in-situ transformed to its salt of lithium 2,2’-bis[benzene-1,4-bis(olate)] (BP4OLi) on Al foil. The resulting BP4OLi is a Li-rich organic cathode and exhibits very good cell performance. For example, the average capacity of ∼155 mAh g^-1 for the BP4OLi electrode is realized during 600 cycles (500 mA g^-1). On the other hand, after setting oxidation in the 1^st cycle (oxidation→reduction), BP4OH can be in-situ tuned to its oxidized state of 2,2’-bis(1,4-benzoquinone) (BBQ). Interestingly, the resulting BBQ can be still redox-active and show satisfactory cell performance. For instance, the average capacity of ∼101 mAh g^-1 for the BBQ electrode can be obtained for 600 cycles (500 mA g^-1). This work reveals very interesting redox behaviors of organic electrodes.

首次合成了2,2'，5,5'-四羟基联苯（BP4OH）的有机小分子，作为锂离子电池的新有机阴极。在设置锂离子半电池的^第一个循环的还原（还原→氧化）后，可以将BP4OH原位转化为其锂2,2'-双[苯-1,4-双（油酸酯）]的盐（BP4OLi）在铝箔上。所得的BP4OLi是富含锂的有机阴极，并具有非常好的电池性能。例如，BP4OLi电极在600个循环（500 mA g ^-1）期间实现了约155 mAh g ^-1的平均容量。在另一方面，在经过了1设置氧化^ST在循环（氧化→还原）过程中，BP4OH可以原位调节至其氧化态的2,2'-双（1,4-苯醌）（BBQ）。有趣的是，所得的烧烤料仍具有氧化还原活性，并显示出令人满意的电池性能。例如，对于600个循环（500 mA g ^-1），烧烤电极的平均容量约为101 mAh g ^-1。这项工作揭示了有机电极非常有趣的氧化还原行为。