A Low-Strain Potassium-Rich Prussian Blue Analogue Cathode for High Power Potassium-Ion Batteries.
Angew Chem Int Ed Engl 2021;
60:13050-13056. [PMID:
33780584 DOI:
10.1002/anie.202103475]
[Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Indexed: 12/21/2022]
Abstract
Most of the cathode materials for potassium ion batteries (PIBs) suffer from poor structural stability due to the large ionic radius of K+ , resulting in poor cycling stability. Here we report a low-strain potassium-rich K1.84 Ni[Fe(CN)6 ]0.88 ⋅0.49 H2 O (KNiHCF) as a cathode material for PIBs. The as-prepared KNiHCF cathode can deliver reversible discharge capacity of 62.8 mAh g-1 at 100 mA g-1 , with a high discharge voltage of 3.82 V. It can also achieve a superior rate performance of 45.8 mAh g-1 at 5000 mA g-1 , with a capacity retention of 88.6 % after 100 cycles. The superior performance of KNiHCF cathode results from low-strain de-/intercalation mechanism, intrinsic semiconductor property and low potassium diffusion energy barrier. The high power density and long-term stability of KNiHCF//graphite full cell confirmed the feasibility of K-rich KNiHCF cathode in PIBs. This work provides guidance to develop Prussian blue analogues as cathode materials for PIBs.
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