One polymer with three charge states for two types of lithium-ion batteries with different characteristics as needed

Abstract

Organic batteries materials exhibit merits of diverse structures, high capacities, less pollution and abundant sources, therefore, developing high-performance organic electrode materials is promising for the next generation of rechargeable batteries. Various advanced organic cathode materials have been reported but most of them possess only two charge states and can be used for one kind of battery. Thus, it is challenging to design organic material with three charge states for two types of high-performance organic batteries with different characteristics as needed. Herein, we designed and synthesized a polymer named P-BQPZ, which integrates maximum n-type and p-type redox-active moieties into one stable polymer with minimum redox-inactive moieties, and thus it can be used for two types of long-life lithium-ion batteries with different features (e.g. high capacity or output potential) by using different redox-active sites. The cathode half-cell based on n-type redox-active reaction exhibits a high capacity of 431.3 mA h g−1 (2.4 V vs Li/Li+) at 50 mA g−1 and a high retention of 99.95% per cycle up to 500 cycles at 1,000 mA g−1. Furthermore, the cathode half-cell based on p-type redox-active reaction displays relatively high output voltage of 3.1 V (vs Li/Li+, 176.6 mA h g−1 at 50 mA g−1) and superior retention of 99.97% per cycle at 500 mA g−1 for 1,000 cycles. More importantly, two kinds of all-organic batteries by using P-BQPZ cathode also operate well.