## 1 Introduction  
Mudstone is one of the more common rocks in Chinese open-pit coal mine slopes, which is characterized by a short rock formation time, structural incompleteness, and poor cementation [1]. This leads to its softness, obvious creep after stress, and sensitive hydrological properties when exposed to water; thus, the presence of mudstone layers can have a serious impact on slope stability [2]. Solving the stability problem of mudstone-containing slopes is of great significance to engineering practice. However, the special nature of mudstone makes it more difficult to solve the problem of mudstone reinforcement in engineering, especially mudstone with poor permeability, obvious softening in water, and easily creeping deformation. For example, the slope of Xiaodnogan open-pit mine contains three layers of low-strength mudstone interlayers, and the slope stabilization strength tends to decrease significantly under the influence of long-term mining operation activities [3]. The landslide on the north slope of the Fushun West open-pit mine was caused by precipitation infiltration that increased the water content of the mudstone layer in the slope, leading to accelerated creep deformation of the north slope [4]. Grouting reinforcement [5] and anchor cable anchoring [6] are the main conventional methods to reinforce slopes. However, the permeability of mudstone is extremely poor, and soft plastic creep deformation predominates over fracture damage [7]. Considering the construction cost and the timeliness of open-pit mine slopes, the above methods are seldom applied to the reinforcement of mudstone-containing slopes in open-pit mines [8]. The solution to the problem of reinforcing slopes containing mudstone in open-pit mines can start from the mudstone itself by changing its hydrophysical or mechanical properties to increase the shear strength of the mudstone and then improving the stability of the slope [9]. [PERSON] et al. investigated the mechanical behaviour of mudstone under temperature and found that the linear Mohr-Coulomb criterion can characterize the shear behaviour of mudstone before and after heat treatment [10]. A small reduction of about 4% in the peak friction angle was observed after thermal treatment at 500 \({}^{\circ}\)C, while the cohesion increased by about 47%. [PERSON] et al. found that the addition of lime basalt fibres significantly improved the water sensitivity and water swelling of red mudstone, with the cohesion being more than 14 times higher than that of untreated red mudstone when the fibre content was 0.2% and the lime content was 4% [11]. [PERSON] et al. found that laser irradiation can improve the strength of the soft rock [12]. Compared with the above modification methods, the electrochemical modification technique causes less disturbance and damage to the original slope morphology, and the reinforcement effect is targeted. In the 1930s, electrochemical technology began to be introduced into the reinforcement of weak rock and soil, using electric current fields to achieve electroosmotic drainage and electrode reactions to form anti-slip piles for reinforcement, thereby improving the bearing capacity of weak rock and soil [13]. In 2014, [PERSON] et al. first proposed using electrochemical technology to reinforce slopes at the Fourth International Conference on Surface Geological Improvement Systems, highlighting the method's superiority in environmental protection and economy compared to traditional methods [14]. [PERSON] et al. carried out electrochemically modified reinforcement on a slope in England, which improved the slope angle compared to the soil nail support method used the previous year [15]. A 29% reduction in construction costs and a 40% reduction in carbon emissions demonstrated that the method can be applied in engineering practice. This method becomes even more energy-efficient and environmentally friendly if renewable energy sources such as wind and solar power can be used to drive the electrochemical modification of the reinforcement.