The electrochemical properties and the cathode densities of the blended cathodes for Lithium Manganese Iron Phosphate (LiMn_0.7Fe_0.3PO₄;LMFP73) and Lithium Nickel Manganese Cobalt Oxide (LiNi_0.5Co_0.2Mn_0.3O₂;NMC532)ratio for LMFP73:NMC532=90:10– LMFP73:NMC532=60:40 (mass%)were evaluated. The cross-section SEM image of the blended cathode for LMFP73 and NMC532 showed that NMC532 particles were well dispersed around LMFP particles. Blended cathode densities were improved with increasing NMC531 ratio.

　The results of electrochemical properties, LMFP73:NMC532=70:30 exhibited superior rate properties to LMFP73:NMC532=90:10, 80:20, and 60:40. LMFP73:NMC532=70:30 showed similar cycling performance to LMFP73. In addition, the blended cathodes for LMFP73 and NMC532 showed lower charge transfer resistance than LMFP73 cathode. Furthermore, for dQ/dV plots of the discharge curves of the blended cathodes for LMFP73 and NMC532, reduction peaks assigned to Ni²⁺/Ni⁴⁺ in NMC532 were observed at NMC532 blending ratio of LMFP73:NMC532=70:30 and higher. These results suggest that the reductions of Fe²⁺/Fe³⁺ and Mn²⁺/Mn³⁺ in LMFP73 occur along with reduction of Ni²⁺/Ni⁴⁺ in NMC532.

　This study investigates the reuse of residual solids from concrete sludge, dewatered using a filter press technique, which were added to cement mortar mixes in place of JIS standard sand. An ordinary Portland cement mortar was mixed with differing ratios of residual solid (50, 75, and 100 mass%), which produced mortars that had a significantly lower compressive strength than mortar without additives. The compressive strength of mortar mixes containing Type B equivalent cement (which is a 60:40 blend of ordinary Portland cement and blast furnace slag fine powder) combined with differing ratios of residual solids (10, 20, 30, 40, 50, 75, and 100 mass%) was then tested, which showed that compressive strength was not significantly lower in mortar mixes containing up to 40 mass% residual solids when compared to mortar without additives. This may be due to the blast furnace slag activating the residual solids. In the sulfuric acid resistance test, the Type B cement mortar mixes were immersed in 5 and 10 mass% sulfuric acid solutions, with high sulfuric acid resistance shown at a 5 mass% sulfuric acid concentration. These results confirm that the mortar meets the standards of the Japan Sewage Works Agency.