Next-generation lithium-battery cathodes often involve the growth of lithium-rich phases, which enable specific capacities that are 2-3 times higher than insertion cathode materials, such as lithium cobalt oxide. Here, we investigated battery chemistry previously deemed irreversible in which lithium oxide, a lithium-rich phase, grows through the reduction of the nitrate anion in a lithium nitrate-based molten salt at 150 °C. Using a suite of independent characterization techniques, we demonstrated that a Ni nanoparticle catalyst enables the reversible growth and dissolution of micrometre-sized lithium oxide crystals through the effective catalysis of nitrate reduction and nitrite oxidation, which results in high cathode areal capacities (~12 mAh cm-2). These results enable a rechargeable battery system that has a full-cell theoretical specific energy of 1,579 Wh kg-1, in which a molten nitrate salt serves as both an active material and the electrolyte.

中文翻译：

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基于通过硝酸盐阴离子氧化还原的氧化锂生长的可充电电池化学。

下一代锂电池阴极通常涉及富锂相的生长，这使比容量比插入阴极材料（例如钴酸锂）高2-3倍。在这里，我们研究了以前认为不可逆的电池化学，其中氧化锂（一种富锂相）通过在150℃下基于硝酸锂的熔融盐中硝酸根阴离子的还原而生长。使用一套独立的表征技术，我们证明了镍纳米颗粒催化剂能够通过有效催化硝酸盐还原和亚硝酸盐氧化而实现微米级氧化锂晶体的可逆生长和溶解，从而产生高的阴极面积容量（约12 mAh）厘米2）。